There are several things you might want to consider before deciding which truck you buy. Probably the most important thing to consider is what parts support you have locally. It doesn't matter what you get if you can't drive it because you are waiting on parts. See what you can get parts for locally and use that as a starting point. Next, what conditions will you be running in? Do you plan on racing, or just bashing in your backyard? Then, you should look at what fits in your price range.
If you don't plan to race, then the Traxxas Rustler or Stampede would be great. The 2.5 is a power house and the trucks are some of the most durable out there.
If you ever plan to race then you might look to the Losi XXX-NT or the Associated RC10-GT. They will not be quite as durable for bashing, but they are leaps and bounds over Traxxas for racing.
Another option is the new Duratrax Nitro Evader. It is relatively new on the market, but if it is anything like it's electric counterpart it will be a good truck for the money.