Your favorite catchy J-Pop songs?

Something like these two tracks, both coincidentally are from the game, Metal Gear Solid Peace Walker...

First there is Inori No Uta, my absolute favorite Japanese pop song ever:

http://www.youtube.com/watch?v=9Phk_egG9-U

That's the vocaloid version.

This is the original version, which is still pretty good but I prefer the vocaloid one.

http://www.youtube.com/watch?v=FLP5PypNO3s

Then there is also Koi No Yokushiryoku

http://www.youtube.com/watch?v=QQJ6LmHM8N0