The answer to 'why vote' is the easy one. Unless you were a property-owning man, the right to vote was a hard-fought achievement (all adult women in the UK only finally gaining this right in 1928). I'm with EM Forster. Democracy is not a perfect system, but it's better than the alternatives:
It's important to vote - for any of the above (on the 'use it or lose it' principle). If you want to vote for 'none of the above', then it's preferable to turn up and 'spoil' your ballot paper than not to turn up at all.
"So two cheers for democracy: one because it admits variety and two because it permits criticism."
Best of all, though, democracy is not a one-way street. If you think the existing lot are no good and you could do better than all of them - then for a £500 deposit and a few signatures you can stand for election next time round.
The clue to how I'm voting is embedded above. Like Forster, I'm a (small l) liberal.
Cameron's Conservatives have made a pitch for this ground - but I reject their instinctive anti-Europeanism and feel that their resistance to electoral reform, against their own interests in this election, is plain stupid. Besides, the linguistic nonsense of 'Vote for Change - Vote Conservative' rankles.
Brownite statism has clearly run its course (ID cards anyone?).
So despite living in a safe seat and knowing that my vote won't elect my MP, I'm voting Liberal Democrat.
Lib Dem tax proposals, though probably not affordable at present, are radical. But I disagree with their aspiration on student fees. On their own principle of fairness, everyone benefits from a health service and from state pensions. But why is it fair to use a plumber's taxes to pay for a lawyer's daughter to train as a doctor?
Yet I'm spurred by the prospect that after the votes are in, two things will count. The first is the number of MPs (the ability to command a majority in the House of Commons); the second is the count of the popular vote.
The Labour party may gain a lower share of the popular vote than the Lib Dems, but will certainly gain more MPs. This would be 'two boos' for parliamentary democracy. Let the people speak!