You could argue that Yes is one, in that the lead singer in which ever line-up you look at didn't share lead vocals... Jon Anderson sings lead on every album but Drama.
The Fratellis are another with Jon Fratelli being the lead singer.
I think most of the obvious ones have been said so I can't think of any more.
CAKE is easily a one-man-vocal show, with some backing and harmonies. John McCrea deadpans every song on every album...
They're still great.
Hitting Bottom Isn't A Weekend Retreat.
Not sure if I already said this, but with Bright Eyes, for better or worse (depending on how you feel about his voice) Conor Oberst pretty much always takes lead vocal
I don't know if it's been mentioned, but in Radiohead Thom Yorke handles most lead work, although Ed O'Brien does add backing vocals sometimes. Also, Led Zeppelin had Robert Plant mainly singing the lead, with the other members occassionally chipping in with background.
R. I. P Syd Barrett (06/01/46-07/07/06)
R. I. P Rick Wright (28/07/43-15/09/08)
"We don't want no trouble, we just want the right to be different. That's all." - pita
The Animals, I'm pretty sure Eric sang all their songs.
I'm not so sure about the Yardbirds, I think Keith sang all as far as I know or remember hearing, but I could be wrong.
I wish Procol Harum would have done the same for A Salty Dog....