If you enjoy the Dance Dance Revolution games, definitely take a look at the Red Octane dance pad. This is much better than the default pad that comes with the game, and helps you play the game more easily.
First, the basics of DDR games if you've never played them. A fun song plays on your gaming system, and arrows move up the screen that you are supposed to press with your feet. So if you see a LEFT arrow, you hit the left arrow with your left foot. Sounds easy - but as the songs go up in difficulty, you are dancing around at a quite rapid pace! Just look on YouTube for some amazing examples of DDR Footwork.
So once you get yourself hooked on DDR - which is a great workout by the way - you quickly realize that the default foot pad that comes with the game is pretty rough. It slides all over the place and causes you to miss notes. It's very frustrating if you fail in a song because the pad is a bad one.
This is where the Red Octane pad comes in. It works with PS1 and PS2 games, so it's good for both systems. It is the exact size and shape as the other pads, so there is no "learning curve". It has a very grippy underside, so when you're dancing and moving around, the pad isn't sliding around beneath you. The buttons are very sensitive so it knows when you hit something.
I had heard some people complain that the arrow foot areas were "too big" - i.e. that if you stand on the center of the pad you might accidentally hit an arrow you didn't mean to hit. I'm not having this problem at all. I'm a pretty "casual" dancer too, so my footwork is not precise. If there was going to be a problem I think I would have it :) So I think this pad is good in this area.
Now it is not IMMOBILE. I have my pad on top of a rubber mat, to give myself a bit of extra grip and cushion. Even with the rubber mat beneath this pad there is still a SLIGHT movement on more active songs. So I'm going to get a pair of velcro glue-on dots and put those in the corners, to ensure the mat stays still. A super easy fix to a minor problem. Still, this mat is far superior than the basic one in this area.
If I were going to have a complaint it is that the hard-surface mats are much better for the super fast dances, but those also cost four times as much. So if you want to go for the really fast dancing you probably want to save up your money for the hard surface mat. But if paying over $100 for a dance mat seems extremely to you, then definitely check this one out. It's well worth the money!
Buy the Red Octane DDR Mat from Amazon.com