It's so difficult to choose just one person since the entire cast, Warblers included, is just so amazing and talented.
I think I'd have to pick Darren Criss for my glee crush because he's incredibly down to earth and isn't afraid to be himself. He is really talented and has a lovely voice.
...also, he plays the dapper blazer-wearing Blaine Warbler Anderson who makes a certain Kurt Hummel happy and happy Kurt makes me happy. Darren and Chris are able to convey so much emotion in their scenes; they really are wonderful actors.