If you have a little wiggle room in your budget I would suggest looking at a used Chevrolet SS. It's a bad *** sedan weighing just shy of 4,000lbs with the 6.2L LS3 mated to a 6 speed! Basically the newer version of a G8 with in my opinion a far better design. Some other good options would be a used Buick Regal GS, Mitsubishi Evo, Subaru WRX or STi, Audi S4, BMW M3, Infiniti Q50, Kia Stinger or VW Passat TDI or V6 to name a few. Keep in mind some of these cars such as the Audi and BMW will need to be a few years older than the other cars to be in your price point. But a nice used Audi S4 with the V8 would be a fun car!
In my opinion Chargers are junk and I would steer clear of them. Everyone I have that I've met or known who had a Charger or Challenger had issues with it. Only FCA product I'd purchase is probably the Hellcat or Demon.
I wouldn't doubt it if the older models were faster. Subaru has really shot themselves in the foot by not updating the vehicles drivetrain in over 10 years. During that same time period the cars have gotten heavier because of new safety features and regulations. With that being said I still do love my 2005 Subaru WRX. Got it as my first car when I turned 16 back in 2005. Currently the car is sitting at my parents house with a mint 52,000 miles.