Great idea Marc (sorry about the consistent mis-spell....I'm a bit of a spelling Nazi too, so there's no excuse), just the sort of undertaking that I enjoy. And you're right that jazz, sometimes, is all about who's playing.

I will start with a few top-o'-my head faves (in absolutely no order):

Lee Morgan - Search for the New Land
Booker Ervin - The Freedom Book
Miles - Milestones
Bill Evans - Interplay
Wayne Shorter - Night Dreamer

Looking at the list of leaders, I could have named other recordings of theirs (three or four others in some cases) just as easily. This whole top 50 thing will be intriguing - some serious culling will be required. How can we get consensus on the positions?