Favorite Steve moment? Most of them - I shouldn't be saying that as a BIG fan of him/his work myself, but there was one moment that I found less than pleasing (*see below).
Least favorite moment? I know he was just going off of a script, but I remember him saying some disgusting things in 'Swamp Years', both as Kermit and the Jackrabbit (*shudder*). Again, I'm fully aware he wasn't actually saying that stuff as himself, but that sort of humor...it's totally unlike him (or maybe weak direction/writing is to blame). That aside, I also obviously didn't like when he got fired. Still mad about that now (judge all you want!)
*Is the fridge joke still going? If so, whose fridge is everyone in now, and is there room for one more?