For DS:
Ontamara - if you like DDRish games, but this has some EBAish element in there too.
Taiko no Tatsujin 1/2 - I love this, so does my girlfriend
For PSP:
DJMAX 1+2 (DJMAX 2 has superior systems, and it supports Link Disc feature which allows you to use DJMAX 2 system on DJMAX 1 songs, but unless you have both UMDs get the combined one and use CWCHEAT. DJMAX is basically Beatmania.)
Taiko no Tatsujin Portable 1/2 - Again, Taiko game. PSP version has downloadable songs too.
Parappa the Rapper - May take a while to get used to the system but it's fun overall.