judging from your screename and profile, you're coming from NYC, no? you also really seem to like BABBO, but you have all the batali/bast restaurants, so i won't go there.
couple of things you don't have are the intensely over the top variety of chinese (yes, not even in NYC's chinatown), taquerias, korean food, and the plethora of high-quality sushi restaurants (we're talking masa-quality).
here's a couple of ideas:
DIN TAI FUNG for XLBdumplings in arcadia, only US outpost
not really low, low food, prime meats, great experience
TACOS VILLAS CORONAS, atwater, lunch only
YUCA's, los feliz, lunch only
LA ESTRELLA, altadena drive only, open until 2am, for fish tacos
OSTERIA ANGELINI, if you think BABBOs good
OPUS, as recommended, go with the tasting menu, can't believe what a value this is
and of course, in NYC, you can't have dinner at the beach w/o driving out to the island or the shore, so CATCH at casa del mar in santa monica, have drinks next store at SHUTTERS first, the catch sunset over dinner at 7:45pm. this might hurt the bank.
if going up to malibu, stop at MALIBU VILLAGE WINES to get a great summer white or rosé and continue to MALIBU SEAFOOD for outdoor eating across from the beach. make sure you make reservations at the GETTY VILLA and hang out on the beach at the ADAMSON HOUSE at about 5pm and watch the tidewater goby and steelhead trout jump for an hour in the malibu lagoon.
buen provecho and safe travels.
Can I third on Opus? Really, it's a great spot for value, service, food, and wine (the waitstaff is great at pairing wines).
And second on Cafe des Artistes. It's yummy--I recommend the steak tartare with frites. But avoid the apple tart for dessert--the crust is soggy, and the ice cream is boring.
Also, Hirozen on Beverly Blvd. and Orlando (east of the Beverly Center) is a good choice. Innovative without being all poseur/fusion, and the purple yam yokan is one of my favorite desserts EVER.
Katana on Sunset Blvd. has strong drinks and good robata grill items. Foie gras-asparagus-filet mignon skewer is a must.
Lala's on Melrose (west of La Brea) has good sandwiches, a funky atmosphere, and nice servers. Plus, you can walk off your meal by staking a stroll down Melrose and people-watching.
Enjoy your trip!
You're at the Roosevelt? Even if you don't eat there, get a drink at Yamahiros, it's on the hill above you. The building is one of the oldest in HOllywood and has that '20's hollywood vibe. Great atmosphere, older posts will tell you touristy and lousy food. Recently they've made great changes and the food is good to very good, but you will have fun, great crowd, great drinks, and even the most picky chowhounds will agree the NUMBER ONE best view in LA. Go for the drinks, and then ask the diners coming out. Bad revues enjoy the drink, the view, the vibe and move on.
Definitely DON'T eat at Yamashiro- the changes were really not all that great-but you could get an overpriced average drink and enjoy the view.
You may want to frm up hotel reservations soon, if you plan on being here for a weekend!
I aways reccomend people go to Little Ethiopia on fairfax for A combo platter at Rahel or Messob. The food will blow your mind, but be aware that ethiopians take life a little slower than Americans,
North on Fairfax is the Original farmers market, a true LA experience with lots of eateries. Loteria and a few others are populat, avois monsueir marcel. The donut place there is fabulous.
Perhaps do one dinner and a brunch? Inn of the Seventh Ray in Topanga canyon has a great brunch buffet on Sundays, a great outdoor atmosphere, and, again, is a tru LA experience.
If you are fixed on Dinner, than perhaps the Saddle Peak lodge and their yummy game offerings are more to your taste?
Dan Tana's is good for old-time LA, as Musso and Frank's can be
Who can come to LA without a visit to langer's for lunch (closed saturday) for the best Pastrami in the US. or pehaps Phillipe's for an original frech dip (I hear most people prefer the lamb).
Definitely second the idea of Ethiopian.
But, depending where you're coming from, I'd suggest getting a Mexican and a Thai meal in while in LA. That said, I'd recommend heading over to Sanamluang or Jitlada Thai. For Mexican, perhaps Guelaguetza is close enough. For Peruvian, Los Balcones de Peru on Vine.
For sushi, I'd say more value at Sushi Ike than Hirozen if you're looking to not break the bank. Katana suggested below is okay but not for one of two LA dinners.
For a really "can't get elsewhere dinner," you could do Palms Thai for the Elvis...
One other idea might be to head over to the Sawtelle corridor.