British accents in general, though not all of them. But I'm not really familiar with the different accents (I can identify a strong Cockney by name and that's about it), so I'm not sure which in particular I'd like/dislike.
Irish and Scottish accents are cool too, though if Moriarty's any indication, I know even less about those. (I would not have pegged him as Irish...more "British with odd pronunciation", or "American trying to sound British". Sorry DX)
Outside of the British Isles, I like Russian accents. Australian too--although Steve Irwin's makes me flinch (and apparently it does the same thing for actual Australians?) I like Hugh Jackman's accent though.
Sorry to the OP and anyone with one, but I don't like French accents. Never have ~_~
I don't like Southern American accents either--which, given I've lived my whole life in the Southern US, means I don't like my own accent. :|
Am I the only one, or does "accent" no longer sound like a word? DX