Personally, I thought the ending was stupid.
It's amazing how the gunshots from Matt's gun arn't quick enough to
kill Sylar, yet Hiro has time to shout "SYLAR!", and take about 2
seconds to rush towards him with a sword, and that's quick enough
to kill him.
I thought the fight sucked too. It was just Sylar pushing Peter
around at the start, until Nicole stepped in to hit him with a
giant pole. Even after that, the fight still sucked.
Plus, the ending didn't make any sense at all. Peter had told
Claire to be the one to shoot him, because he said "if I start to
go nuclear, only you can get close enough to me", but as we saw,
everyone could go near him when he started glowing.
Also, why couldn't Claire just pull the trigger? All they had to do
was pull the bullet out of his skull after he died, and he'd
automaticly come back to life like Claire did in an earlier
episode.
I suppose the worst case scenario would be that he's unable to come
back to live, but that's still better than having his brother fly
him up to the sky so they can both explode together. Besides, can't
Peter just fly himself into the sky, explode, and hopefully he'll
regenerate himself after exploding.
Lastly, we saw in an earlier episode how the invisible man managed
to stop Peter from exploding simply by knocking him out. I'm sure
Nicole had enough strength to do that. Why didn't anyone think
about it? Any other option would've been better because at the
worse, only Peter would die and not Nathan.