Overall i'd have to say the Pop'n Music series is prolly my fav, but like other Bemani games you can only get the full enjoyment out of it by playing with a
Desktop arcade,
djdao, or
Ransai controller. Also i'd suggest checking out Daigasso Band Bros, this was the first game i imported for the DS.
It came with a set of Nintendo headphones and nice poster, a very good game that stills holds up today. It was the first game to use Japan's DS Download service, for downloading extra songs. There was also the Daigasso! Band Brothers Tsuika Kyoku Cartridge (GBA expansion pack) released that included 31 extra songs that could be loaded up if it was in the GBA slot while playing Daigasso
Also the Rhythm Tengoku game by Intelligent Systems on the GBA, it's a must play for anyone into this genre. It received an Excellence Prize for Entertainment at the 2006 Japan Media Arts Festival. It's not a manic Rhythm game like others you might have mentioned, instead it's more of a mini game romp that focuses on timing. The
Official Site is still up if fancy a look.