I know it's personal preference, but I hate when people judge a coaster as good or not based on whether they got a good spin. Yeah, the spinning on a spinning coaster is important, but people need to remember they're on a coaster, not a waltzer. Getting a good spin on a crappy Reverchon mouse doesn't make it any less of a crap coaster.
I think my favourite is actually Comet Express at Lotte World. It doesn't tend to spin a ridiculous amount (though it can nearer the back of the train and if it's unevenly weighted), so if you're judging it based on that, you might not like it. It's just a really long, fun, excellently-themed coaster. It's just a huge surprise the first time around as it's entirely underground and you don't realise from the tiny entrance what a "big" ride it actually is.
I never used to rate Sonic Spinball, but the last few times I've ridden it it's really grown on me and I think I prefer it to Dragon's Fury now to be honest.
I enjoyed Tornado at Bakken, apart from the neck chopping. I don't think Intamin have sold another of that type since since, have they? I've got no idea of cost and reliability, but that seems a bit off to me.
Winjas was excellent, but again if you rate these coasters based on their spin, you might not think so.
I can't think of any other standouts to be honest. The thing at Europa was really forceful for a spinner, but it made me feel ill, so I won't say I enjoyed it.
The Golden Horse spinners are ok, as are the models they're ripped off from, but once you've done one, you've done them all. They're just very bland really.
The Reverchon things are s**te. No more to be said on that.
The worst one I've ever done though, apart from some kiddy spinners which don't count, is Spin Bullet at Sega Joypolis (thankfully now gone), which managed to be bland, boring and forceless, yet extremely painful at the same time.