Check out Treadwright. If you don't care about performance/traction, they might have something you like in your budget. That's not to say their tires perform poorly--when used for their intended applications, Treadwright's tires can be quite good.
How aggressive do you want it to be? How little do you care about your traction, ability to stop/accelerate, etc? If you're OK with crappier mpg, more road noise, and less than stellar street (usually especially rain) performance, just look into MT tires and pick the ones you think are aggressive enough.
BFG Rugged Terrain LOOKS rather aggressive in my opinion without actually sacrificing its road manners.
General Grabber AT2 looks aggressive (for its class like the Rug Ter) and behaves well in all conditions for a good price.
Goodyear Duratracs are a bit of an AT-MT hybrid that some consider as being aggressive-looking that still behave well in all conditions.
Build Thread -- http://www.jeepforum.com/forum/f177/whats-chrokeese-build-thread-2525690/