I love DDR!!!  I play it every day.  My favorite songs are: Freckles, Peace (^^) \/, Ki-Se-Ki, Daikenkai, Love is Orange, Sana Molette Ne Ente, Quickening, Tsugaru, Take Me Away, Love at First Sight, Heaven, In The Navy '99, Afronova Primeval, and Seduction.  Read about DDR and look at pictures here:

DDR first version for PS1

2nd version for PS1

3rd version for PS1

1st version for PS2

2nd version for PS2

3rd version for PS2

4th version for PS2 ^

newest DDR game ^

coming this fall ^