I'd have to say the Mugen MST-1 especially since you can get one for $130 bucks at Nitrohouse.com, and I think it's $350 or $400 with the motor. you could buy two trucks for the price of everything else
Besides the cheapness factor, you get a truck that's basically a losi, just beefed up with thicker arms, and 1/8th scale bladder shocks!
I already bought one and a new engine for a total of $250, and I still have money in my budget to get a mugen pipe for $80 bucks, and a new servo for $75
TeamXray RCAmerica Hudy Xlgraphicspro Paint/ Impulse-Rc Clutch shoes.
Xray XB 808 O.S. Speed Or Ninja JX