Any of the four Team Associated RC18 platforms (RC18T, RC18B, RC18R or RC18MT).
RC18T is the "truck":
RC18B is the "buggy":
RC18R is the "race-car":
RC18MT is the "monster truck":
Team Associated also just launched the RC18T2 and RC18B2. These are nearly identical chassis setups, with the major differences being the RC18T2/B2 use a belt driven system rather than the shaft driven system in the previous models (RC18T/B/R/MT). I would recommend the first edition (RC18T/B/R/MT) just because the system is tested and proven while the T2/B2 is new to the market; and, also, in my opinion, shafts are easier to maintain than belts (but that is mostly preference).
Another major difference between the first editions and the T2/B2 is the T2/B2 is a kit and the first editions are complete ready-to-runs. Comes with the TX/RX, ESC, motor, and even the 7.2V NiMH for the car. All you'll need to purchase is the eight AA batteries for the transmitter!
Cheers,
Kyle.