Try Lee's Barbecue in Haslet. It's a tiny dump of a place, basically a one man operation, and that man is might, mighty good. I've eaten barbecue in over 200 Texas counties, and Lee's is one of my all time favorites.
Best pork ribs I know, and outstanding brisket, sausage and hot links. The pork loin ranges from very good to great, and I've never had the chicken. The baked beans are also great, and all the other sides are at least good.
Take 35W south to Highway 114 (it's exit 70), go west on 114 a couple of miles, then take 156 south to Haslet. Turn left across the railroad tracks. Lee's is in the only building you'll see. Do NOT try to take 35W to Westport Parkway, which is what Mapquest will tell you to do, because there is a little bridge on Westport Parkway that is closed for repairs and you'll have to make a ten mile detour if you try.
If you do go, please send me a note or do a post to let me know what you think.
I've gotta disagree on this one.
I went to Clark's this summer (posted somewhere below), and I was underwhelmed by my experience. I didn't smell any smoke outside, didn't see a woodpile, and the brisket was merely average. I'm under the impression this place has dropped a bit from it's glory days.