And you got it through good fortune: lets say you sold a company, part went into retirement, part to crap your wife wants (Er I mean WE WANT HONEY LOVE YOU!), and this is your "FUN CAR" chunk. Point is, you're not going to run into 50k stray cash again any time soon. You'll probably start having babies soon, in fact, so you need to buy a car that is
1.) Fun to Drive
2.) Self Maintainable for a reasonably handy guy with a lift at his disposal
3.) will hold up well for the next 10-18 years (when your kids move out and it's finally time to get a new one!)
4.) Trackable (I want to go play on HPDE days)
What do you get and why? Please note, despite the belief, Miata isn't the answer here.
I'm partial to the idea of a C6 Corvette, or a late-ish model Viper. Having owned and worked on Corvettes myself I know I can do most tasks there, so that's a plus. The viper seems just as mechanically simple.
Ninja Edit: This does not need to be DD Worthy. I work from home and have a worthy DD if I need to go somewhere in the winter.