I am soooo sorry to be so late to this- have had the week from hell, and completely forgotten about it, not even logged into email! And then when the instructions said 'logout of MN' I was a bit
bunny in the headlights! 
I try not to be swayed by the leader of a party, but I vote at each election (including local) according to the policies and manifestos of the parties- I try to read them all for the main parties standing in my ward/constituency. I think this is because there is no party that is remotely similar to my ideology for life, and I have to pick and choose the policies I support most (well- often it comes down to whose policies do I dislike the least actually, because like another poster above, I would never NOT vote).
I would like party leaders to be people of integrity. To be well-educated, well-informed, and most of all to have the country's best interests at heart, and to make decisions based upon what is best for the citizens of our nation rather than their party's or their own interests. AS IF that would ever happen? 
Unfortunately, I think that even people who go into politics with the best intentions end up being corrupted by the system, once they have their snouts in the trough- just look at what goes on with the expenses system! People 'flipping' multiple properties
employing their relatives
getting their mistresses elected to easy council seats (LibDem and Labour in my city
)
At the 2010 General Election, I did something I've never, ever done, and am unlikely to ever do again- I voted Labour. It was a tactical vote, due to the area I live in, and the other candidates. I would have voted LibDem (they came 3rd), however I have the misfortune to know their candidate personally, and I could not vote for him with a clear conscience as I find him morally repugnant. I did not agree with many of the policies in the Conservative (came 4th) manifesto, nor Respect's manifesto (came 2nd), and even more in the UKIP manifesto! 
Oh yes, bloody marvellous choices I had- I disagreed with many of the Labour proposed policies too, but I had to vote, so they got it. They won- the MP has been MP in this seat for many, many years- he has the dubious honour of being the MP that attended the fewest sessions/votes in parliament too

I wouldn't mind, but my street has been in 3 different constituencies for the last 3 general elections! 
And now I've just moved house to a different constituency anyway 
If I had voted LibDem, I'd have been pretty bloody angry to find them in coalition with the conservatives after the election tbh, and would have felt ripped off.
My Dh voted Conservative, and he's pretty cross about how things have turned out (yes, I know people said what would happen, but still, I think he was expecting better of them tbh).
I just don't feel that any political party represents what I want for the UK. The closest is often the Green party, but they don't always have candidates (I have voted for them quite a bit previously, but seemed to be fewer candidates recently, and the area I live in is never going to elect anything non red a Green. I honestly could not say who I would vote for in a general election tomorrow- unlikely to be any of the big parties. I am angry that the gap between rich and poor is getting larger. I think social inequality is very harmful to society, and would like to see the trend on this reversed.
I think really I believe in the 'benign dictator' model of state- a dictatorship is the only way to actually change things, to get things done, but that dictator must be a good person, moral and just, a protector of the weak and poor, and nurture all in our society. Clearly this is unlikely ever to occur! I also think that to be successful in politics, really, you have to be a sociopath- and sociopaths are often not nurturing, good people with sound ethics.
Actually- I may revise my statement above. I have just looked up who my MP is now I've moved- it's actually someone I know (I have met a number of politicians, local and national, for various reasons, personal and work-related). She is Labour, however I think she has integrity, and reasonable morals, though her faith may lead her to vote against what I believe is right in areas such as abortion rights etc. We'll see what their policies are I suppose, but I don't think I could vote for the Labour party tomorrow judging by their last couple of years in opposition. I despair, I really do. I've met Ed Miliband, (thanks MNHQ
) but I think the labour membership chose the wrong Miliband. But better Ed Miliband than Ed Balls eh?(met him too!) 