Dream Musical Collaborations

What two artists would you love to see working together?  Two huge bands together, or one huge band with a small, local sound? 

Lately I have heard some awesome collaborations, and they seem to be happening more and more often among artists that I never thought would get together.

My dream collaboration though would have to be Muse playing alongside Juanes.  Muse is my absolute favorite band and Juanes is my favorite Latin singer.  I can just hear Bellamy on the piano, with Juanes singing something along the lines of A Dios le Pido before Bellamy cuts him off and goes into a straight minute in that falsetto voice of his. 

Ahh, almost too much for me to handle.  Though I would much rather forget that and just wait to see what they come up on their own.