Oh, yes! I almost forget! You can play real media and quicktime files too on WMP, just install the Quicktime Alternative and the Real Alternative (only the components you REALLY need, discharge all extra useless components - MPC is great, though). Yes, probably when you try to play these files with WMP it will tell you that it does not recognise the format but just click on YES and VOILA!
I think it's the best, it's useless to install the quicktime player and the awful Real Player to play each format. You just need the "codecs", that's it.
I highly recommend MPC, it uses even less resources than WMP, for those who doesn't really bother on having all the skinny beautiful GUI of WMP.
Have a nice day!
PS: I would use Winamp, but it doesn't have a native way to show lyrics saved in the tags. Yeah I know I can install an add on, but I want the feature to be NATIVE, don't wanna install any messy little program on any player just to watch some lyrics! Not big deal.