British male here, and uh... Russian accent, or even any slavic accent really gives me shivers. And that's not because of the 'Russian bride' stereotype!
To be honest though, nearly any European accent sounds wonderfully attractive to my ears. A girl with a thick European accent of any description is likely to make me melt like butter. I suppose i like Russian / Slavic the most simply because of how different it sounds and that Slavs tend to look very distinctive - their accent compliments their appearance in terms of how alien and different it is, and i love that.
I'm really not keen on any British accent. In fact, it can all drive me crazy. Us southerners sound like we're condescending and have a stick up our arse, northerners are sometimes hard to understand (same goes for Welsh and Scottish). Irish is tolerable, but it's just not that attractive on a lady. Might have something to do with this stereotypical angry Irish 40-something chemistry teacher several years back. I'm just not keen on the American accent at all because to my ears it sounds like a drunk version of our dialect / language. For you Scandinavians out there, American is to me what Danish is to Swedish (and vice versa)