I would have to say The Clash in 78 and Ian Dury and the Blockheads in 79 and Japan also in 79'ish.
Ian Dury would probably take the #1 spot by a nose.
I put these three over the gazzillion times I've seen Bowie, because I expect an amazing show to see the great one, but wasn't expecting too much for these, so they in effect "blew me away."