Standard stuff:
Accord - new ones are big
Taurus - big and reasonably nice but boring, SHO might be fun
5-series - fun until it breaks
E-class - nice but boring
Infiniti M37/45 - most of the BMW excitement but with Japanese reliability
Lexus GS - RWD, marginally more exciting than a Camry
Acura TL - reliable but dull
Subi Legacy/Impreza/Outback/Baja - lots of Subi options, many with turbos and a stick
Audi A6 - beautiful inside, typical German reliability
Volvo S60 - somewhere between the Germans and Japanese
Mazda6 - worth a look, $25k would buy a nearly new one. In Grand Touring guise they are quite nice and pretty decent to drive.
Altima - rental car
Maxima - fancy rental car
300/Charger - rental car
Impala - rental car
Optima - rental car
Probably some other appliances that I am forgetting....
Fun stuff:
CTS-V - you can get a really nice 1st gen CTS-V with plenty of cash left over. It's a four door Corvette with a stick, how can you go wrong? They are also pretty solid reliable cars, though a little on the small side.
Subi - worth a look at the WRX, STi, Legacy GT, and XT models. All get you AWD, turbo-four, and a stick.
S60R - Also fun, can be had with a stick.
V70R - who doesn't love a fast wagon?
E55/E63 - you can get either for $25k. The E63 is a beast, the engine is an all time great. I LOVED my C63.
E39 M5 - some love them, I was personally underwhelmed.
RS6 - lots of power, not known for being reliable.
XJR - air suspension makes them a little scary.
XFR - supposedly rivaled an M5 when new, auto only.
D3 S8 - another one known for air suspension issues, but stunning cars.
Pontiac G8 - an outlier here, but RWD with V8 power. GXP added stick but are still pricey.
Lexus ISF - a little small, but it's a super sedan by Toyota.
Mazdaspeed6 - you have to go back to the previous bodystyle, but you get almost 300 HP, AWD, and a stick.
Happy shopping, let me know if I can help.
