It seems like the streaming-media market is made up of evils and lesser-evils (Ogg and MP3 excepted, for the most part). And, when presented with a choice, I’ve never been sure whether it'd be more ethical to choose Windows Media or RealPlayer (since public support tends to legitimize a format).
Recently, I’ve been going with RealPlayer over Windows Media since at least it’s available as a cross-platform application. All the same, RealVirus (as some like to call it) is still one of the most user-hostile applications I’ve ever seen.
It plays .RA, .RAM, and .RMI files (which isn’t all RealAudio content, but it meets my simple needs.) It appears to be free of spy-, ad- or nag-ware, and (outside of some initial twiddling with the file associations) it appears to work perfectly. I tested the software on Real’s test site.
For a bit more info, see the discussion in “alt.comp.freeware” with the subject line “Real Audio Codecs”. It began on 4/15/2003. This link might get you there.
Update: Real also provides archived versions of its software — RealPlayer 8, anyone?