Believe me or not, I'm using Win98SE that has only 4.0 MB space on the prime hard disk and 4.1 MB on the secondary (sorry, I might not know the proper words but you get the point? Anyway, I have even less disk space than Yvan256).
I used only WinAmp until two weeks ago, I think. That was when I got frustrated with one song in mpc format that couldn't be played on my mp3 player. So I went to the Internet and searched for a freeware converter. What I found and downloaded after taking a look at the features was not only a converter but also a player, MediaMonkey.
MediaMonkey supports every file format I know and some that I have never heard of, it's compatible to iPod and many other portable audio devices (I don't think it is with mine but I don't even know what kind of mp3 player I have, at least not iPod

), has the music library feature etc.
http://www.mediamonkey.com/
The not-so-good things about the player is that it tends to have problems sometimes ('The canvas does not allow drawing' or 'MediaMonkey can not create a DC to [artist - title]' or something like that, I have no idea what those are about but I don't think it's too often at all and the problem might be only on my cpu, I'm not sure. Anyway, that's only up to 1 time a day as far as I know and I don't have to restart my cpu, either) and, of course, with so many features, it requires a bit more ram than for example Wa.
Oh, and if I want to edit tags, I must do it in MediaMonkey and not WinAmp. Don't ask me why.
I still like Winamp 2 and I use it, too, when I'm doing something else that requires a lot of ram.
I'm not sure if this helped you in any way since you already were satisfied with Wa.