In search of great steak or Mex Mex
Stephan Pyles for high end southwestern/south american food and great steak selections. N9ne for great steaks and sides and a cool area to walk around (victory plaza). Javiers or Lanny's for mexican. Of the steak places you mentioned, id skip Bob's and go to Perry's or Al's. Bur Id take N9ne over both of them. If you do go to Perry's, get the brown bag apple pie. Its one of the best desserts in town.
I haven't actually eaten there, but if you're looking for high end mexican I think the answer is Lanny's Alta Cocina Mexicana. Essentially it's a guy who busted his chops in an outrageously popular tex-mex joint, then stepped back and applied French technique to genuine mexican (pre and post columbian). I've never heard a foul word spoken of it, and I would guess that someone with NYC food leanings would be intrigued by what he's doing. Other's with more experience there should chime in and share if what I've said is accurate.
Other than that, I'll bet the Mexican food you get in New York is better, since everything here becomes Tex-Mex eventually.
I know it may be a little heretical for a Texan to say this, but there are very good steakhouses in NYC (Lugers, BLT Prime, Craftsteak) that aren't that much more of a wallet beating than what you find in Dallas. If you want to try a meal unique to Texas, more specifically to Dallas, I would suggest going to Stephen Pyles (which does an excellent steak). For Mex-Mex, I would suggest Cafe San Miguel which I prefer over Javier's.
If I was coming to Dallas from NYC, I would definitely do Javier's . It has Mexican and SW items , plus a great steak with a good sauce . The sauce is not a mole , but it's close , and it's delicious .I must ask , why would someone from NYC look to eat steak when they are away from home ; I ask , in as much as you guys pretty well invented the high end steaexperience , and have yet to relinquish your title .