I think this is possibly the best calculation I've ever made in a correspondence game. Black to move and win:

Obviously there are ways for Black to stop this by jettisoning a pawn or two, but this is how the game played out. This is the critical line if White tries to hold onto his material (he actually starts a pawn down).

3... Bxf3+

True! Don't know how I missed that, thanks for pointing it out. In that case the key move is even better. (With a lot less calculation needed too!)

Very cool! Thanks for sharing.

Very nice! except again yeah 3. Bxf3 I was like LET ME. WHY. oh, rook x queen? :D

I must say I got it in one go. Its a very tactics trainer like puzzle. hmm :P

Thanks Krames and ShadowKnight. Yeah, the move leapt out at me immediately too! Just calculating (wrongly in my case) what happens after Rf4!