There's so much great barbeque around here that the list gets long quick.
407, Goldee's, Panther City, Daynes, are what come to mind on the Fort Worth side.
Terry Black's, Pecan Lodge, Lockhart, Slow Bone, and Cattleack on the Dallas side.
Meshack's in Garland is a great spot for ribs. No seating.
Tex-mex/Mexican - Avila's in Dallas is awesome. Ojeda's just down the road from it is pretty darn good, too. El Pueblo in Oak Cliff makes great Mexican food, but they sometimes hit folks with a "gringo tax" and some folks find the neighborhood a little sketchy. La Mexicana up in Denton is good - great migas. Joe T. Garcia's is a Fort Worth institution. There's a local chain called Blue Goose Cantina that lots of folks like.
Norma's Cafe in Oak Cliff and Mama's Daughters Diner (original is Dallas Design District) are home-cookin' classics (I think Norma's is better). All Good Cafe in Deep Ellum is worthwhile (great everything, but the chili, chicken fried steak, and bacon are all noteworthy). Rodeo Goat (several locations) has great burgers. Easy Slider in Deep Ellum is great, too. If a gastropub is something you want to check out, maybe try Meddlesome Moth in Dallas. A pretty nice restaurant in downtown Fort Worth is Reata.