I doubt any of them would make what I would consider to be 'great' parents, at least as they are now. But, by the time they wind up actually having children, they may wind up having changed somewhat...though I wouldn't lay down any odds.
And, of course, we don't know exactly how all of them view parenthood, which may be more or less important than might be assumed...we know that Ukyo fantasizes about children on occasion, that Ranma didn't apparently think his father having a bastard child and leaving it behind was a particularly big deal, and Kodachi was planning on kidnapping chibi!Ranma, and Shampoo wanted to cuddle him, though how much is because they like children and how much they like Ranma is possibly questionable. And Mousse doesn't mind smacking children that look like Ranma and Ryouga. That's about all I can think of off the top of my head.
But yeah, short answer: None. Some might be more or less tolerable, but I doubt any would be great.