Add me on to the Clemenza train.

He's easily more likeable than any of the others. Look at the scene where he's teaching Mike to drop the gun after shooting Sollozzo; there's real affection there (on Clemenza's part towards Michael).

Clemenza is something of a comical escape. The scene in flashback where he and Vito steal the carpet is hilarious, as is the (deleted) scene in which he sits down and eats an entire meal while Paulie waits in the car.

And remember, it was Clemenza whom Vito trusted to accompany Michael back from Sicily (in "The Sicilian").