Well what are you into?
I like American cars so although I started with an S15 I have been quite enjoying a tuned Camaro SS '10. About 500HP (with supercharger) and lightened to the max it never feels like it runs out of steam. The gear ratios were bad though so I installed a 6spd close-ratio transmission and use one gear above what I think I should initiate in. The supercharger allows me to have enough power in the higher gear to do what I need to.
Other than that I have a Lexus LFA that I drift stock with comfort tires but it feels a bit weird, kind of like the power is too peaky and the gear ratios aren't really that good for drifting.
Thinking about getting a Z06 or ZR1 plus the previous generation Viper to add to the collection.