Quicktime works great on Macs? What world are you living in? It takes over all my file associations (Bad Apple!) cannot be removed (Bad Apple!) and still can crash Firefox (Bad Apple!)

It does work quite well, I'll say that, better on Windows, but for me I wish I could just control it more!
But, on Windows, I suffice with Media Player Classic and an install which includes the Quicktime codecs for media (
in a mega pack, which is not always the best idea, but works fine for me. Careful if you delve into installing it blindly. I'm fine, it's all I use

) - I've never been on a necessary site which *requires* Quicktime, so my Firefox just flags up it is needed to play it and that's that. Sorry, that wasn't much help...however...
...The same site provides a guide to
installing quicktime (in a good way), and
removing it too, which might be your ticket to a better install!
Then there is
Quicktime Alternative (which is probably how the mega pack plays quicktime things). Not sure about browser compatibility.
I also only currently run XP and Firefox 2.0 (until a plugin I use is updated, I'm happy). Firefox 3.0 has a "Plugins" panel next to "Addons" - if Quicktime is there, you might want to uninstall or find some "Firefox without Quicktime" guide. If you install the mega pack though and don't care about quicktime at all, it'll remove it anyway.
One thing I should get around to doing is checking out if I can install quicktime somewhere, have it lie dormant, then attach only to Opera which I have as my secondary browser, allowing me to get on all the hip and happening Quicktime sites
