Joey
Matt Leblanc gets a shot on his own. Now everyone knows that I'm a big Friends fan, but I really do believe that the show was carried by the Joey character in its last four seasons.
At any rate, I hope it works, but I don't know if the writing will be enough to sustain it. The writing is why Frasier worked, to the point where it developed its own identity completely apart from Cheers. I doubt Joey will accomplish that, but we'll see.
So, will it go the way of Frasier or Sheriff Lobo? I think it'll last three years--the loyalty of Friends fans will sustain it that long. Beyond that, who knows.

UPDATE
Well THAT certainly wasn't anything special. The other characters in the show couldn't be less interesting. Ugh.