I'll hop onto the Say Yeah!, Genki+ and Ikimasshoi bandwagons and add Onna no Yuujou Mondai, Never Forget, Dream & Kiss, Hand Made City, Sayonara no Kawari ni, Densha no Futari and Honki de Atsui Theme Song. ^^
(BTW, I remember hearing that Say Yeah! was originally going to be the single after The Peace! but that fans didn't like it when it was performed so RR21 became the single instead [kinda like the Chokkan 2 situation])