In OKC,
For burgers, 2 places:
1) Nic's Burgers--for onion burgers, which is a traditional OKC recipe which came about during the depression, where cooks would save hamburger by using fried onions as filler in burgers.
http://www.eataroundokc.com/nics-gri...oklahoma-city/
2) S&B Burger Joint--more traditional burgers and sliders, very creative combinations
http://sandbburgersokc.com/
For BBQ:
1) Iron Starr BBQ--calls itself "urban" BBQ. It's sort of upscale, very unique, extremely well done BBQ.
2) Leon's BBQ or Bedlam BBQ--tossup between these for your more traditional paper-towels-on-the-tables sort of joints.
For steak:
1) Red Prime--(pretty upscale, last time I went it was about $150/plate), steaks are excellent, 40-day dry aged. Sides are exquisite. They have a halfway decent happy hour as well.
2) Cattleman's--this is a more classic restaurant. It's more than 100 years old, which is significant since OKC was only settled in 1889, located in the middle of the stockyards. Their meat is wet-aged according in a process they claim is a secret. If you're brave, try the lamb fries (which are battered and fried testicles from steers).
http://www.cattlemensrestaurant.com/
Most unique:
Bobo's Chicken
This is a food truck which parks on lot at NE 23rd Street & MLK in OKC and is open up (not dependably) around 9PM and is open well into the night. Expect long lines. If you're travelling and don't know the city very well, this is in a very sketchy part of town, there have been shootings, but nothing random. They serve either fried chicken wings, fried catfish or fried shrimp. Go for the chicken. It comes with honey and rolls which I'm pretty sure are fried. The chicken is smoked and fried.
http://www.urbanspoon.com/r/46/15151...-Oklahoma-City
We also have a number of unique localvore type things popping up. Our whole food scene is getting fairly trendy as of late.