What a dangerous question. This could take a while...

My super-seekrit guilty pleasure pairing in the classical genre is Sherlock Holmes and Dr. Watson.

My current movie fondest wish in the movie department is The Comedian and Ozymandias.

My tv-show wishlist of pairings is kind of long: Johnny Smith/Walt Bannerman (The Dead Zone)
Mulder/Krycek (X-Files)
Rube/Mason (Dead Like Me)
Oz/Anybody (Buffy)
Angel/Lindesy (Angel)
Wesley/Gunn (Angel)
Fraser/Ray K (Due South)
Jim/Blair (The Sentinel)
House/Wilson. And this is even canon, people. Yes, it is. (House)
and I'll stop there.

The comic book pairing that does it for me is Wolverine and Gambit.
Hell, ANYTHING Gambit floats my boat.

I perv on games, as well.
Zack/Cloud/Sephiroth, not limited to threesomes. (FFVII)
Issac/Felix (Golden Sun). Don't judge me.
Sora/Riku (KHI)
Roxas/Axel (KHII)


An' thats the short of it. Over-active imaginations ftw!