You can battle Cynthia in BW2 after beating the Champion and going to Undella Town.

The Nostalgia Dump

Pokemon OR/AS Wally Theme Remix

The Legend of Zelda: Majora's Mask - Stone Tower Temple soundtrack.

Some Tracks out of my favorite pokemon game of all time. 

N's (Or should I say Natural Harmonia Gropius')battle theme from Pokemon Black 2 and White 2 for Nintendo DS.

The unused (or hidden, I'm not really sure) World Champion Blue battle theme from Pokemon Black and White on Nintendo DS.