As Dan says, a 370Z is pretty much your best bet.
I'm gonna make an assumption your criteria is along the lines of:
- < 7 years
- <50k miles
- <6 secs 0-60
- (Semi-)Auto
- RWD
- Sporty Coupe
- Reliable and relatively cheap to maintain
Personally, I'd instantly rule out anything German, unless you are buying new, so no VAG stuff, Mercs or Bimmers.
The Alfa Romeo Giulietta, Focus RS, Peugoet 308 GTI, Renault Megane Renaultsport, Seat Leon Cupra, and Vauxhall Astra GTC are all FWD hatchbacks and probably only as reliable as the 370Z if not less so.
If you don't mind compromising and getting a sedan, you could potentially pick up:
Mitsubishi Evo X - Excellent performance, but AWD and repair bills will be even higher
Lexus GS 450h - Bulletproof, but a bit boring. CVTs are no fun either
Subaru WRX - Another AWD, but might be a bit better for reliability
Jaguar XF V6 - Reliability is supposed to be pretty good on Jags these days, but a 370 is still gonna be more fun and probably cheaper to run
The only other option, which admittedly is VAG, but probably beats the 370Z in every way is a Porsche Cayman / Boxster. They are supposed to be very reliable, but if something does go wrong, the bills can get scary big, and fast.
So there you have it, the 370Z is the best mix of performance and reliability. Get one