I see a lot of videogame music covers which make their way over to Weekend Destructainment quite frequently. For the most part, they're usually good covers but it's been rare, especially as of late, to find great covers. Enter WaltzForLuma, and her amazing piano arrangements of various videogame songs.
As her name is based on the game, Luma's YouTube contains a large number of Super Mario Galaxy covers. Other games include Final Fantasy, Secret of Mana and various Zelda games. I picked a few of my favorite pieces for your enjoyment here and there's plenty more over on her YouTube.
The Legend of Zelda: Windwaker - "Dragon Roost Island"
Final Fantasy X - "Besaid Island"
The Legend of Zelda: Adventure of Link - "Palace theme"
Super Mario Galaxy 2 - "Main theme"
Skies of Arcadia - "Fina's Theme"