Pop'n Party
I played this game for the first time at a Japanese Animation convention, and for the entire weekend there was a line waiting to play this game. With good reason too, I had a blast and I'm totally new to the game! Too cute for words!

Incredible game
Pop'N Music 9 features a ton of songs, ranging from great levels of difficulty, so it's great for beginners looking to start out in this wonderful series of Bemani games. Be sure to get a controller too, otherwise your experience will be greatly hampered.

Pop'n Music 9 Rocks
This version has a great mix of songs both new and old and with favorites that DDR and IIDX players alike will know, it's a good place to start into this fun series of games.