YouGov show Clegg winning the 1st debate
Leaving aside your own party preference, who do you think performed best overall in tonight’s debate? Gordon Brown 19% David Cameron 29% Nick Clegg 51% Don’t know 2%
Angus Reid have a page where you can watch the answers to their survey coming in here. I'm not sure when it closes, but so far it too shows Clegg winning followed by Cameron then Brown.
UPDATE: ComRes appear to be showing Clegg 46%, Cameron 26%, Brown 20% as the winner - so all three polls show Clegg winning by a large margin, with Cameron in second.