We can keep talking for ever about which electoral system is the best, but first we have to persuade people that there are electoral systems better than FPTP.
As it happens my favourite system is cellular constituencies, invented by the 'who should you vote for' website. It works like this.
Halve the number of constituencies to around 323. Voters cast their vote in exactly the same way as under FPTP by putting a cross next to their chosen candidate. The winning candidate in each constituency is elected PLUS the 323 candidates with the most votes nationally. A candidate could stand in as many constituencies as they like to maximise their chances and if elected would represent the areas their constituencies covered. In practise this would mean that each party would stand roughly the number of candidates they think will win, either in a single constituency, regionally or nationally.
The advantages of this system are we would get more proportional results without losing voter accountability and it is simple for voters and administrators to understand. It would also mean virtually every elector would have an elected representative from their particular political party to turn to for advice.
It is likely that knowing your vote will count towards electing a candidate will change the voting habits of the electorate and also the policies and kind of parties standing for election. But this aside lets look at how the recent general election results would have been reflected in parliament under this cellular system (current seats in brackets). I've kept the number of seats the same as at present at 646 for easy comparison sakes. Of course this number could and probably should be reduced to around 500 (a more reasonable size for a legislature), but that is an unrelated point.
For the first time UKIP, the Greens and the BNP would have representatives under this result, 10,5 and 2 respectively. It is likely that the number of other MPs would be much higher than this as voters wouldn't have to vote tactically anymore but could vote for the party they like the best, even if a minor party. I know some people will wince at the prospect of 2 BNP MPs, but bringing their policies into the open is the best way to highlight their ridiculous policies and discourage the nearly 200,000 people who voted for them! Also a 5% threshold could be introduced to discourage minority parties like the BNP.