[rab] If you vote Labour or LibDem, either could contribute toward the continuation of the Lib/Lab coalition, as the SNP wouldn't win the seat anyway. OTOH, if the SNP look like they're in with a chance, you need to vote for the party most likely to hold them off (which I would guess would be the LDs in Edin South, unless the boundary changes have altered things). Personally, given the state of the planet, I tend to vote Green in regional lists (e.g. GLA and EU elections) as it seems to be the only way for them to ever win a seat. Don't really agree with all their policies but I naively trust that it helps with pushing the environment a little further up the agenda.
(For that matter, I notice that the polls are suggesting the Greens could fall back to 1 MSP this time (from 7 last), so if you want to help shore up their position, Green would be a good way to go in the lists).
I've just received my polling card for next month's Assembly election, so I've been pondering too. I live in a Labour donkey district, so it can feel a bit pointless, but then there are the regional lists to vote for as well. Libdems would seem to be the most likely to get in on this one, but I'm greatly annoyed at the vast quantity of crappy "newspapers" they keep pushing through my letterbox. One of them wasn't even identified as party political except in teeny-tiny writing at the very bottom of the back page.
[Projoy] A crap reason for voting green would be that I actually know, and like, the third person on the regional list (we currently have 2 on our regional list).
[snorgle] Oh dear! I often hear other people complain that they'll vote for x party because "they were the only one that bothered to send me anything saying what they believed in". Damned if they do, damned if they don't, clearly!