Expectations
Caroline Forbes always had high expectations of her dream guy. She imagined her boyfriend as someone who is smart, good looking and athletic.
He cares deeply for her and constantly shows it. She is the most important person to him. Of course that also means that he sees her as more than the ditzy blonde cheerleader that most people at school believe her to be. Of course, he is not just focused on her looks, but is interested in what she has to say as well.
Furthermore, he will never even glance at other women and get just the right amount of jealous when she talks to other guys.
After she becomes a vampire she also needs him not to smell too tasty and accept her for what she is without fear or disgust.
For Damon's sake she adds a no-compulsion-clause, even though she knows nobody should be able to do that to her anymore anyway. Him not having more supernatural drama going on in his life than her would probably help too and whenever hers get too much for her to deal with, Prince Charming is going to be there for her.
Yes, Caroline Forbes always had high expectations of her dream guy and while Tyler may not fulfill all of those the only thing that matters in the end is that she loves him.