I love Geordie, ala Cheryl Cole. I also really like the southern Irish, and the Welsh too - but not the thick, heavy Welsh.
Scots is a funny one. I like it on a guy (as in, talking to a Scottish guy, not for punting
) but I don't like it on a woman. I used to work with a Scottish guy, and his accent was hilarious when he's ranting about something. But on a woman, it's actually a turn off for me.
American is ok, but it really depends where abouts in the US the accent is from. I love the bold, brash, New York accent, but the LA "whine" pisses me off. Texas is great on a guy, but again, on a woman - doesn't do it for me. I think I like southern hick accents on woman; call me objectifying and crass, but there's something about a dumb/ditzy blonde chick with a southern hick accent!
French - take it or leave it. Can be sexy, but can be fucking annoying. Italians just sound angry. Spanish talk to fast, and Russians just sound scary!