I've been really digging the Chevy Corvette C5 Z06 lately. Nice and strong, pretty forgiving, but still enough power to get yourself in trouble if you don't respect it. Think it'd be a good intro to American muscle. There's also a premium '09 ZR1 'Vette, 600-ish supercharged horses. Wild.
The 2014 Corvette [C7] is also ridiculously good, quite a bit less tame than the Z06 but the handling on the '14 is far more nimble.
Avoid the Mustang Shelby GT500 like the plague, its a heavy ill-handling brute. '05 Ford GT is just buckets full of MR fast though.
For Old-School muscle, either of the the '69 Camaros [z/28 or SS] are great, as is the '70 Nova SS. And of course the 2 60's era Vette's, the '63 is pretty prone to understeer though, so I'd recommend either of the '69 models.
SRT Vipers are a pretty good bet, but not really my taste as they have a really heavy feel to them. The ACR is the best of the bunch though, it has adjustable downforce front and back.
If you've got the cash or the 15th Anniversary disc, go for the Shelby Daytona Coupe. Unreal.
All cars mentioned are Premium.
