Barrry's Pizza on Richmond is my favorite. Star Pizza is second. Everything else is way down on the list.
I like Fuzzy's Pizza on 1-10 and Antoine. I haven't been to any of the other places named here so it wins by lack of my experience.
Definitely Grimaldi's followed by Pink's Pizza. Luigi's is awesome as well. I hear good things about Brother's though. Haven't tried that yet.
I am a big fan of this place called Crespo's Pizza. It is on Westheimer, just inside the Beltway. Awesome pizza!
I'm surprised that it took 4 pages for someone to mention Barry's. I love their deepdish pizza. EDIT: Guess I missed the last post on the first page. Anyway, Barry's is great.
Pi Pizza Truck (http://www.pipizzatruck.com/) Its a Pizza Food truck that runs around the Montrose, Heights and Midtown area. Check em out yall, they have different off the wall pies. Their menu is on their site and they deliver as well. Other than Pi Pizza, there's: Star Pink's Fuzzy
My faves, in no particular order: Grimaldi's Romano's Capones Dolce Vita Best bar pizza is at Kennealy's Candelari's has a cool pizza happy hour during the week where you can get whole thin-crust European style pies for like $7-$8.
Big fan of the wheat thin crust grilled chicken, pepperoni and jalapeno pizza from Candelari's off upper Washington. Right around the corner from my house, so it always arrives hot and fresh. Their lasagna is the bomb as well.