In that case, the best BBQ in the world (see, e.g., http://www.slate.com/id/2118542/ ) is in Lockhart, about 30 minutes east of Austin. It's somewhat controversial as to which place in Lockhart--Kreuz's, Smitty's, or Black's--has the best stuff, but IMO it's all good.
Also, this was a particularly good post about a road trip in the area. http://www.chowhound.com/topics/458851
I don't think you'd be disappointed if you followed in this poster's footsteps, except that I would not recommend Papacito's (overpriced chain Tex-mex).
One more thing I'd recommend for a true taste of Austin is Magnolia Cafe (http://www.cafemagnolia.com/). Try the "Neptunian Landscape" (homefries + cheese + salsa). Magnolia's menu is diner/tex-mex/hippie--Austin in a nutshell.
please dont take his advice about magnolia cafe (or kerbey lane, or huts, or the other myriad of "austin institutions" forced down our throats by advertising dollars and idiotic college students), there are countless better places to go late night for both taste and service
also, tex-mex is for insecure white people, you gotta get back to the source ya heard (a few words of advice - NEVER GET LETTUCE AND TOMATOES, cilantro y cebolla 4lyfe)
here are the places id recommend hitting up having tried them personally
hog island deli (16th/lavaca) - the best sandwiches and cheesesteaks in town
belladonna (burleson/ben white) - breakfast/lunch, their muffalettas off the chain
rosie's al pastor (parker/riverside) - theyre open until 3:30 every night, and are by far the best late night dining option in austin ive tried
taqueria el risconsito (manor/airport) - breakfast/lunch, best tacos in the town that ive tried
reggies (12th/chicon) - best catfish around but you never know if hes gonna be there
galloways (12th/chicon) - you can always count on a good meal here
springhill catfish - about as good as reggies and a lot more reliable, plus they got BUFFET. THATS RIGHT, A BUFFET OF CATFISH.
seis mesas (springdale/airport) - breakfast/lunch, great cheap food
burgertex - some of the best burgers around
el regio - best drivethru in austin
willies bbq (mlk/airport) - best bbq ive tried in town
sams bbq (12th/pleasant valley) - pretty good bbq, also open late at night
asia cafe (spicewood springs/183) - best chinese in town
t&s chinese (lamar/rundberg) - the salt&pepper dishes are great, plus theyre also open late night
eastside cafe (manor/chestnut) - just ate here a couple days ago, their stuff is fresh (literally, like they got gardens and ish), plus their soups really good
stallion cafe (51st/airport) - breakfast/lunch, probably the second best drivethru in austin after el regio (that ive been to at least)
madam mams - an austin institution but for the right reasons, their stuff is usually very good
al jons pizza (burton/oltorf) - i used to live right across the street from this place, some of the best pizza ive had in austin (tho ive not been lucky enough to go to vespaio which is rumored to be better)
yaghis - also very good pizza
jo's - get their burgers cause boy are they good (tho on the sly ive heard casino el caminos is the best)
by no means am i master at this stuff, so my recommendation is just go through these threads, find out who the smart people are, and find out for yourself what youll like
hope i helped 8)
I have to second that warning about Magnolia Cafe--it IS a pretty good example of Austin culture--relaxed, nice people, etc.--but the food is crummy (and I love diner food).
As mentioned before, you truly can't go wrong eating barbecue in Lockhart, as long as you go to either Kreuz Market or Smitty's. Stay away from Black's or any of the other pretenders--Smitty's and Kreuz are where it's at.
I am white, but I'm not feeling particularly insecure, so I'll chip in that my favorite Tex-Mex is Enchiladas y mas on Anderson Lane. It's great stuff, incredibly caloric and thoroughly delicious, as Tex-Mex should be. I always get the same thing; cheese enchiladas with chili sauce. I've tasted many other things on the menu and have yet to find a dud. In the morning, the migas con queso are some of the best in town. You have to eat Migas while you're in town. It's the classic Austin breakfast.
For barbecue, there is one place in town that on a good day has brisket and sausage that rivals the boys in Lockhart: House Park Barbecue. It's just west of Lamar on 12th and is only open weekdays from 11:00 to 2:30. My usual is a brisket and sausage sandwich (why choose?) because the sides aren't that great. I also find their chicken lacking, with a tough skin and meat that's just OK.
Definitely start with one of (or all of) the 3 BBQ places mentioned above. The BBQ in Central Texas is unlike BBQ in the world, and those places are the best to get it.
Where to find the best mexican/tex-mex/gringo-mex is a hot topic on the Austin board. It depends on what you want, whether authentic Mexican that you could find in Mexico, or the cuisine that the Mexicans that immigrated to Texas developed (authentic Tex-Mex), or the cuisine that has been changed for more American tastes (not-so-authentic Tex-Mex, or gringo-mex as it's called around here). In my opinion, they are all delicious in their own way.
For the more authentic Tex-Mex take a look at this thread: http://www.chowhound.com/topics/93317
If you will be here on a Saturday or Sunday, there is a flea market that has a ton of taco trucks (our version of street food), some of which have been reviewed in this thread: http://www.chowhound.com/topics/461905. Although, one warning- there may be a bit of a language barrier.
For the not-so-authentic Tex-Mex there are a few places head and shoulders above the others. Las Manitas on Congress is good, esp. for breakfast, and has a lot of Austin culture. If you'll be downtown it's a good stop. Jorge's and Enchiladas Y Mas have been mentioned a few times for this kind of food. I'm a fan of Maudie's, but it doesn't always get a lot of love around here. Places to avoid (but often recommended to out-of-towners by people who don't know what they're talking about): Chuy's, Trudy's, Gueros, and Matt's El Rancho.
If you want chicken fried steak, here's a thread: http://www.chowhound.com/topics/93088
As for the Magnolia Cafe suggestion... It's a place that is very "Austin-y" with all kinds of art on the walls, servers with interesting haircuts and piercings, and a very wide range of guests, but not great food. Breakfast and late night (such as after a night on 6th street) are the only times I'll eat there. Stick to breakfast and appetizers (queso, the martian landscapes at Mag) and you'll be OK.
If you want a break from all the heavy eating and are a fan of Whole Foods, check out their corporate HQ and mega-store on Lamar between 5th and 6th streets. It has 5 or so restaurant kiosks inside the store where your meal is cooked in front of you, as well as a mega salad bar, hot food bar, sandwiches, pizzas, noodle bowls, raw bar, gelato, etc. It’s really an experience of its own.
Enjoy your time in Austin. Hopefully the weather will be a nice reprieve from NY.
As y'all are New Yorkers, I'd abstain from Austin pizza. Some of it is passable, most of it is pretty bad. In either case, you won't be impressed.
I'm digging the suggestions so far. Most out-of-towners (and all of my local friends) really enjoy Las Manitas' food (breakfast and lunchees only). It is a well-known establishment, located right in the heart of downtown (2nd and Congress), and has been in the news a lot lately (it has managed to hold up the construction of a Marriott or a Hilton or some other gigantic hotel). They do Mexican food, and I really love it. I don't know what the seasoned Chowhound regulars will have to say though.
If you want the VERY best Texas barbecue, go a few more miles south on 183 to City Market in Luling. It beats anything in Lockhart, and that is high praise. Ask for brisket with fat and sausage. Whole sour (not dill) pickle, raw onion, and soda crackers. Forget beans, etc. This is about meat.
I always send out of towners to the original Salt Lick BBQ in Dripping Springs for a combo platter with potato salad. It has great BBQ, prices are not too bad, and terrific atmosphere. I prefer it to Smittys and Kreutz in Lockhart, where the focus is purely brisket with no sauce or interesting sides.
I'm rather new to these boards but I praise myself in having tried a lot of different places here in Austin and I have narrowed certain places down to my 'favs'.
Chinese - Din HO BBQ is a fantastic place that I love going to that is not your typical 'Americanized' Chinese. This place is a great place to eat, but don't expect the best 'service'. I highly recommend the Chinese BBQ pork.
Italian - A lot of differentiating votes on this one but some of my favs are:
Siena Ristorante on 360
Romeo's on Barton Springs (although this place has gone downhill quite a bit over the years due to changes in ownership)
Reale's on 183N is a great little catch if you're up that far north.
BBQ - The Luling and Lockhart info is pretty much what I agree with
Seafood - Heh, no comment
Steaks - Eddie V's and Sullivan's are the only two places that I can think of that offer really cuts and choices of meats although, I prefer Austin Land & Cattle at times simply because of the delicious sauces and those damn mushrooms.
Tex Mex - The afore mentioned tidbits of Chuy's, Trudy's and Guero's and others are perfect must eats.
Lastly, if I were to tell you two place that you HAVE to eat at before you leave Austin even moreso than what I've listed already would be:
Hoover's Restaurant on Manor Rd:
This place I consider an Austin 'institution' simply because of the approach to food, price and atmosphere. You pay for no frills here, you will not get a band interrupting your food, you won't get 'dazzling ambience' either. What you will get is an out of this world dining experience that centers around 'soul food'. Think of food that you would typically eat after church on a hot summer Sunday in the South and this is what you would get. I HIGHLY recommend the smothered Pork Chops (although they are limited as to what day they are served :P). The sides are oustanding as well, especially the jalapeno creamed spinach and black eyed peas. The deserts are pretty good as well from what I've heard. Additionally, they have an applewood smoked chicken quesadilla for an appetizer that is out of this world.
Lastly, if you are craving some true 'Austin' tacos. I recommend Taco Deli. There are 2 locations and I've been to both and the only thing I can say is that I actually have 'dreams' about their tacos. Every single person I have ever sent there is ALWAYS satisfied from their food. Good stuff.
Have fun in Austin!