Despite being a windows user primarily, I'm inclined to agree.
The only way I can get my VCD/SVCD stuff to play seems to be in PowerDVD - WMP just won't play it.
Xine never had any trouble, nor did mplayer.
However, I'm kind of used to using lots of different media programs. On linux I used XMMS for music, Xine (then later mplayer, cos I liked it more) for ripped stuff, and Ogle for DVDs because I found it worked best.
On windows I tend to use winamp for music, WMP for TV episodes, and PowerDVD for ripped films and DVD discs simply because I have 6 channel sound so I'm DAMN well going to use it (PDVD uses Dolby ProLogicII to "guess" the surround sound for plain old stereo rips).