Dance Dance Revolution has become a hugely successful franchise in a time where most of Japan is suffering under a recession. Actually part of the larger Beatmania (Bemani for short) series of games, it's the sort of game people look at and say, "That's easy", until they actually get up and try it. I've seen people sit and laugh at how bad a player is doing on a four-foot song, until their turn rolls around and they are unable to maintain the simplest sense of rhythm on Silent Hill.
While a previous writeup (since removed) has proclaimed DDR as the "game of the chigger", I beg to differ. Personally, I think it's hilarious when some holier than thou "cool" kid steps up and thinks he's going to beat the "nerds", and then all but has an aneurysm trying to make sense of the arrows whipping by on the screen. I do agree, though, that watching people try to play in chains, high heels, baggy jeans or tight skirts is loads of fun.
However, DDR is nothing like what you would do at a club. DDR is Simon with music and feet, matching a predetermined pattern as well as you can. It tests reflexes, coordination, rhythm, and physical fitness -- but it is about as related to dancing as Pong is to table tennis. You get no points for creativity (in fact, it'll often cause you to screw up), and there's no upper body movement to speak of. If it is to be compared to any group activity at all, it is closer to aerobics, calisthenics, or line dancing than anything else.
Now for a miniature rant: I really hate DDR elitists. You know the type; there are ones for every hobby, every game, and every fandom out there. These are the ones who will sit back and scoff at anyone unable to get more than a C on a Catastrophic-level song, or deride newbies to the game. They erupt in a huge temper tantrum if they miss a single step in their massive combo, and storm off in indignant fury if anyone manages to beat them. They feign boredom when playing against someone else, as if to broadcast the message that such competition is so beneath them. These are the insecure types who have to lord their one talent over everyone else to feel good about themselves, and I will not put up with them.
The bottom line is that DDR is a game. You may like it, you may despise it, but it's there for recreation and enjoyment -- both the participants' and the audience's. Treat it as such.
Addendum 01/08/2002: Yes, the song is indeed called Silent Hill, though it has nothing to do with the horror FPS Playstation game of the same name. It is, rather, a slow Christmas ballad. And yes, perhaps the miniature rant on elitism is misplaced, but it was annoying the heck out of me. Being a dick won't get people interested in your game. And if people aren't interested in your game, Konami won't support it. And if Konami won't support it, it will disappear. And then where will your 1337 skills be?