The Big Bang Theory, Season 3

Penny:
Oh, yeah, you can't sit there.

Bernadette:
Why not?

Leonard:
That's where Sheldon sits.

Bernadette:
He can't sit somewhere else?

Penny:
Oh no, you see in the winter, that seat is close enough the the radiator so he's warm yet not so close that he sweats. In the summer it's directly in the path of a cross-breeze created by opening windows there and there. It faces the television at an angle that isn't direct so he can still talk to everybody yet not so wide that the picture looks distorted.

Sheldon:
Perhaps there's hope for you after all.