Fast cars I've driven:
Buick GN
Subaru WRX
Mitsu 3000GTVR4
99 Supra Turbo
99 Porsche 944
9? Mercedes 300
00 Mustang GT
I've driven a lot of fast cars, honestly I felt safer in the MB than in anything else while going over 125mph. It's a solid car that is geared to run 100+ all day long.
Acceleration wise, the 3000GTVR4 is hard to beat for brute acceleration. Mainly because of the all wheel drive and twin turbos. However, due to the turbos it is necessary to launch at high rpms which will shorten the drive shaft and clutch life in such a heavy car.
The 944 was the best balanced car and had the most linear torque curve.
The most fun in a stock car is by and far the GN, those things should be illegal. (for everyone else, and I should have 3)