I find accents which are close to RP but not actually RP attractive. There's a girl I know with such an overdone RP accent that it not only turns me off but pisses me off.
I also find Irish and Australian accents attractive.
I have that, to tell you the truth. I picked it up from my father - trade 'girl' for 'man' in that and you've pretty much hit the nail on the head. Some Scottish accents really take to recieved pronunciation - others fail spectacularly sometimes.
I'd gander that you don't find many here though. Accents across Scotland can be both brutal and brutally applied.
I think I like any accent other than the one where I live, which is sort of northern-y. I can't think of any country outside the UK that doesn't have an utterly awesome accent, actually. They're all great.
Generic? There's nothing generic, really, about any 'Northern' accent, they're all different. You can tell, I'm sure, that I am a Northerner and I speak Lancashire.
I'm not really sure on what accents I find attractive, myself. It depends on the speaker.