I'm American, but I follow British politics pretty closely. I watched the leader's debate the other day, and that was really entertaining, not to mention the fact that, since the outcome doesn't affect me at all, I was able to go into full-blown political analyst mode. Miliband was probably hurt the most, since (A) he was attacked on his left flank by Sturgeon, Bennett, and Wood, and (B) no one really landed any hits on Cameron since he was able to "hide in plain sight," so to speak, due to the number of individuals on the stage. In addition, Miliband is going to have to do it again in a week and a half during the opposition debate while Cameron (and Nick Clegg, but let's face it, he's irrelevant) kick back and relax.
Overall, I'd be surprised if there isn't a hung Parliament. The Liberal Democrats are going to lose too many seats to be a viable coalition partner, and UKIP, the Greens, Plaid Cymru, et al aren't going to earn enough seats either. The only way I see a hung Parliament being avoided is if Labour and the SNP collectively earn enough seats to constitute a majority (which would seriously make a lot of people in England uncomfortable) or if there's a grand coalition, which just isn't going to happen. There's also the possibility of UKIP earning barely enough seats to form a coalition with the Conservatives, but, as of right now, that's even less likely than a grand coalition (since UKIP is currently projected to win ~4 seats).