I like Raj the best because he has a very big heart, is considerate and also the loveable foreigner. I kinda like the fact that he also relates to me in a nerdy way if tu know what I mean. x3
I'm sure that the general answer would be Sheldon, which is a close segundo of mine, but my absolute favorito! would have to be Bernadette. She is adorable and innocent-looking at first, but is vicious and sassy as tu get to know her.