I really like the current crop of V8 Mustangs. Even though I am not a Mustang guy, I rent the Hertz V8's every chance I get. They are a blast to drive.
Ford has done a great job with the engine and suspension. As a complete package, it works very well indeed.
I also like the cabin and gauge lighting options very much. I can adjust for the color I like, a very nice feature. Plus there are some interesting digital gauges (A/F ratio, G's, 0-60 and so on) available if you select them.
Given the choice of all conventional Mustangs, I'd pick the Boss 302, or 5.0 with the track package.