I've got an Associated RC10GT, and I used to race regularly. I've since moved to airplanes, but I keep the RC10GT for when the field is too muddy to fly or all my batteries are on a charger. In the 5 years that I've beat the snot out of it, It hasn't needed anything other replacing one set of rear wheel bearings, tires, and occasionally cleaning the crud out the recoil starter.
Similar to electrics, Associated and Losi are the two everything else is compared to, and you will be able to get replacement parts for them anywhere, even for a buggy that is 20 years old (A friend of mine still runs an Associated TQ10 that I sold him over 10 years ago). Traxxas has improved in the ~15 years they have been in business, but they never really impressed me. Tamiya cars look awesome and have a lot of cool features, but the ABS plastic they use is too fragile.
AVOID KYOSHO AT ALL COSTS! I made the mistake of buying a Kyosho buggy once. Expect them to discontinue anything you buy so you won't be able to find parts. They used to switch distributors almost annually, and they had no US distributor and were completely unavailable about 5 years ago. I heard they have a distributor again, but I haven't followed them since. As soon as I found a used gearset I on Ebay that worked, I sold that hunk of junk. Another friend is still trying to find replacement parts for his old Kyosho USA-1
Stick with one of these:
http://www.losi.com/http://www.teamassociated.com/