I really like XMPlay, but it has a very small flaw that should be possible to get fixed:
Sample rate conversions from 44.1kHz to 48kHz or vice versa produce clearly audible artifacts (aliasing). Interestingly enough, even Audacity of all things has the same problem even when set to the highest SRC quality, while the VLC player has no problems whatsoever regardless of settings.
This is usually not a problem, but I really don't like the idea of resampling and re-encoding some of my stuff that is in 48kHz and in a lossy format.
Here's one of the most obvious examples. The first few seconds are resampled. https://dl.dropboxusercontent.com/u/61111963/SRC%20Artifacts%20XMPlay.flac
I hope there is an easy way to improve the SRC quality, though the fact that even Audacity has the same problem worries me a bit. Still, if VLC player can do it just fine, why can't every program?
Edit: I had an old Audacity version installed. They recently changed their SRC library to libsoxr, which should be better, but apparently the problem is still there. If I convert the file from 44 to 48 back to 44 I notice no difference anymore, but when I listen to either version with my output set to 48kHz, it still produces those artifacts. VLC still doesn't. Very strange.
Edit2: I have found the culprit. It's not the program's internal SRC. It's actually a WaveOut-related problem, even though VLC strangely enough didn't produce the artifacts even with WaveOut selected as output. After installing this fix I have no more problems: http://support.microsoft.com/kb/2653312