I personally enjoy the ambiance of raves. Love the techno/house/trance genres. Both watching and performing light shows (glowsticking/glowstringing) is fun too.
Legal/Illegal raves both have their pros and cons. Legal raves you don't have to worry about cops busting but it doesn't have that underground, "exclusive" feeling warehouse raves do.
Of course, going to any rave sober is a no-no. Have to make sure to be under the influence of MDMA, LSD, and/or 2C-B to fully enjoy the synaesthesia of the music and light trails!
Haven't gone to one in a few years though, but can't say it's my top priority either. You have to be in the right mood for something like that.