I'm very lucky to be married to one of the good ones 
I think his number one awesome quality is acceptance. By which I mean, when we first met I was still pretty messed up from my abusive childhood - next-to-no self-esteem, generally unable to see myself worthy of love etc - and he loved me, and still loves me, for exactly who I am, just the way I am. He has supported, and encouraged, and challenged me even, into learning to love myself, but always from a position of complete love for me just the way I was. I am a very different person (in a good way!) to who I was 9 years ago when we first met, and that is in no small part down to him. (He would also say that it was all me who beat my demons, he was just support - so humility as well)
I had 2 previous relationships with wonderful guys who loved me a lot, but could not handle me in my dark places. It is a rare but wonderful quality.
Also -
Respect
Commitment (Assuming that's what you're looking for)
Sharing of same values/what is important in life
Good communicator
Good Dad (the day I saw my DH-to-be interacting with his young nephews, I knew he would make a great Dad to our kids -and so he's proved to be)
He's not perfect (he has a habit of thinking there's a cleaning fairy who goes round clearing up after him - thanks MIL!), but he's pretty brilliant, my absolute soulmate. He makes me a better person, and I him. 