I've driven every MR car I can get my hands on in the game, and the Lotus Elise is definitely the best handling of the lot. Get the top-end Elise model and run with it. I personally prefer the standard Elise over the "sport" model (under Classics) because it looks better and revs higher. The sport model is, however, lighter and can have slightly more power (thus somewhat faster).
The Elise in RL has received nothing short of stellar reviews in car mags. Road and Track recently called it the "Best handling production sports car" they've ever driven. The GT4 Lotus definitely reflects this.
Also, because the car is light it doesn't need a ton of power to go fast. Tweaked to the max you 331hp, which the Elise, being a MR design, can actually keep on the ground even with sport tires and all Nannies off. What this means is that you won't be sitting there burning rubber while the other cars take off and leave you in the dust.
IMHO the Elise makes the NSX feel like a heavy wet sponge in corners...
