A lot of stuff can hold out well against him in lane.
Udyr, Olaf, Cho, Yorick, Trundle, Nunu and Irelia turn it into a farm fest. I've never lost to a lee sin in lane once you have a glacial shroud you can shrug off his damage unless your behind.
Fiddlesticks wrecks warwick (I love reidan's fiddle). Tristana and MF have the potential to shut him down early with their healing debuffs (i wouldn't try this in low elo). Heavy pushers like Morde don't really beat him, but will at least keep him there. There are a few more, but this is all i can think of right now. He isn't the unstoppable force people make him out to be. Warwick is fairly weak early(pre lvl 4) take advantage of that when you see him picked in ranked. Build MR.