A quick reminder that the UK system is based on individual constituencies and so it's the candidates in your constituencies that are the ones you need to look at first, both in terms of their attitude and in their chance of winning. I am in a constituency where, barring something completely unprecedented, the result is already known. So it doesn't matter which way I vote.
No matter which party (almost!) she was standing for, I'd want to vote for Belinda Brooks-Gordon, for example. She happened to stand for the LibDems in West Suffolk last time, I don't know about this.
skeptical-voter.org/wiki/index.php?title=Belinda_Brooks-Gordon
The coverage of the LibDem debate on safer sex work featuring her mentioned elsewhere here is no longer on the BBC iPlayer, but like all good former 'policy wonks', I have a copy of it.
The Greens may get more votes than the LibDems overall, but - unless there is an enormous change in their support, into the 30% range - they will get many fewer MPs. (Equally, if anyone wants to bet with you that UKIP will get more MPs than the LibDems, take the bet!)