Unlike the hard-core off-roader SUV underpinnings of the Lexus GX 470 and LX 570, the Lexus RX crossover family is primarily designed for on-road duty. Its soft ride, strong V-6 (RX 350) and hybrid (RX 400h) powertrains and luxury accouterments are wildly popular, and the previous RX essentially introduced the whole idea of an SUV that wasn't designed to go off road. Even though the competition has caught up, the original RX SUV is still one of the best.