Hey, now: I've heard the M3 is a pretty healthy machine, but I know nothin' about them other than they're fast. The new ones are butt-ugly, as are almost all the Bimmers. They look like they were drawn up by animators working on Batman/Superman.
But I'd definitely take the oldest M3 series - seems like a simple, straightforward and buildable car. I hear they kick booty beautifully on a track.
BTW Thom, just so you know, M3s are the favorite ride of the Jewish-American Princess down here in SoCal. Hardly a "right"-bend car in Beverly Hills, so to speak.