Compare prices before you buy. Fun, great with a dance pad, gets you off your butt and doing something. Music all sounds the same, if you don't have a dance pad forget it. 3.0 Dance Dance Revolution is, basically, all about getting your groove on.
Difficulty ranges from easy to impossible, getting very hard, very quickly.
From there you pick a song. All of the music is generally the same, all having a light-hearted techno feel. Oh, and you get to pick your character. They dance on the screen, not really following your movements, just kind of doing there on thing. It would have been nice if your character choice affected how you had to dance, it would have added some more much needed variety.