Two are on my list of never hope to ride again:
Ghost Rider (woodie) at Knotts berry farm. I prefer my rides to not make me wonder if I'm going to get off with serious injury. Just from all the sharp bumping combined with forces pulling me in not pain-free directions. I.E. I HATE rough rides.
The Coaster at New York New York, Las Vegas. I didn't think it was possible for a steel coaster to be worse than a woodie, but I was wrong. Not only is it horribly head-banging due to the OSTR, it's also got chunks which are horribly slow AND headbanging at the same time.
I've got a few that I didn't have a good first ride on, but I'm learning how to ride certain coasters better. For instance, I got off Goliath (SFMM), after having a icky grey-out session. But again that day, I was hungry, a bit tired, and slightly stomach sick not due to coasters. Vowed never to get on it again. Now I realize I'd probably enjoy it quite a bit now I'm a bit more 'big coaster' trained.
And on the B&M thing. If I was building a park in my backyard, and could hand pick a handful of rides to have there, almost all of them would be B&M's. Sheikra and possibly Montu from Busch Gardens, Kracken from Sea World. A few others (I'd say scream from SFMM but Kracken is a close sister and has much nicer transitions). Now I think about it, almost of the coasters I have ridden multiple times are B&M's.