MariaZ - that question makes you sound like a man..hmmmm?
To me, it is not about "good-looking" as in the text book definition. It is more about whether he gives you what I call 'the warm fuzzies' - that feeling you get when he walks into the room or you see him. If he doesn't make you feel warm and fuzzy inside, then it is not right.
You have to be physically attracted to him, otherwise you will never be able to have a relationship with him. But, someone who is not text-book attractive can still be attractive to you and give you the warm fuzzies.