SNSD vs. Katy Perry

Hyuna vs. Katy Perry (sorry, I couldn't embed this one ._.)

http://www.youtube.com/watch?v=Dy8D_ePLa00&feature=channel&list=UL

2NE1 vs. B.A.P (ASDFGHJKL B.NE.P!... the dance break is awesome .-.)

http://www.youtube.com/watch?v=uHDlAM4yOwE&feature=channel&list=UL

2NE1 vs. B.A.P (YAY AGAIN)

http://www.youtube.com/watch?v=nju4-vNpmzA&feature=channel&list=UL

Brown Eyed Girls vs. 2NE1 ft. B.A.P

Super Junior vs. Psy ft. Hyuna 

http://www.youtube.com/watch?v=QX3I2t5QrH0&feature=channel&list=UL

B2ST vs. Britney Spears

http://www.youtube.com/watch?v=7jWDrLSVIfs&feature=channel&list=UL

MBLAQ vs. SNSD (this sounds a bit messy, but still sounds pretty cool)

http://www.youtube.com/watch?v=3Vlfn37qeYg&feature=channel&list=UL

~~

And here's another user that I absolutely LOVE as well. Maybe even more than the first guy

Bigbang vs. 2NE1

(this is the single best mashup I've ever heard, legit)

LMFAO vs. Bigbang

http://www.youtube.com/watch?v=hugihAFtzNY&feature=channel&list=UL