Extreme is the newest one and I would recommend that one over DDR2 (I only bought DDR2 Max because my brother already had the Extreme version).
I also recommend giving your son a "just because gift" maybe call it a Winter gift... and you start using it!!! Yes, the Extreme pack comes with one mat, so go out to gamestop and buy a second one for $20... it's well worth it and a ton more fun to challenge people to play against you!

so i still have to wait.

that is too funny!
i am also a fair weather walker. i heard about ddr and all the good it's doing for people who don't like traditional exercise. with your inspiration, i hope i have the same success.(when i can find one that is
).
) I haven't heard of Yourself Fitness. What is it?
so i will just keep checking until their in.