I love Winamp over iTunes because..
a) Winamp doesn't tag your MP3s if they are tagless.
b) WMP has and always had the BEST visualization, plug-ins & skins. Better than WMP & iTunes put together.
c) Winamp doesn't use annoying proprietary meta-data on top of the existing ID3 Tags).
d) Winamp has Smart ID3 Tag Expression Extracter. Used when MP3 is ID3 tagless.
I don't like meta-data. It's useless data for other players that don't use it. I don't even like the MP3 tag IDs because:
a) It gives you 2 (or 3 if you count in both IDv1 & IDv2) sets of file information data to manage/sort/maintain. And even worst, if you use iTunes or WMP then add on top of that another set of meta-data to manage/sort/maintain. It just makes it harder searching for music if you haven't cleaned/sorted/maintained ALL your MP3s in a consistent naming standard.
Na'Mo! ( http://www.somewareonthe.net/) has helped a lot, renaming all my 30,000,000 MP3s into the 'standard' format:
<album name>/<2 digital track number>. <artist> - <track name with no hypens (-)>
Then using ID3 Tag software to massively clear/remove all TAGs (both IDv1 + IDv2). Not just blanking them. Actually removing the space allocations for them. Hence saving space.
If you only need the 4 information: album, track #, artist & track name then you don't need tags. If you need year, genre, tempo, etc. then that's fine.
And the best thing about Winamp is the Media Library & Play List intelligently extracts the meta-data out of the file name (if it's tagless). And it uses the floating meta-data to sort, etc. Very nice.
The thing about the above 'standard' naming format is because not only Winamp uses it, but I found other players use it. Virtual DJ, for example. And this is not from customizing or programming the naming expression. It's all pre-defined. Virtual DJ has nice Smart Tag Extracter as well.
PS: I like do iTunes. I just wanted to suggest some wishlist things for player.