What are some good VGM songs or albums with Japanese vocals? Any recommendations?
I'm studying Japanese and would like to surround myself with the language as much as possible.

Surely there must be vocal covers of obvious stuff like FF, Chrono, Castlevania and Mega Man (http://www.youtube.com/watch?v=Lsj0mY13t9s)?

Only one I can think of off the top of my head at the moment is Suteki da ne from FFX sung by RIKKI - it was only sung in Japanese, even in the US/European version of the game, with an English arrangement only being recorded recently as part of the Distant Worlds concert album.

Other than that, you might also like to try the original Japanese version of Melodies of Life from FFIX sung by Emiko Shiratori (although the US/European version of the game had English lyrics). The original Japanese recording however is available on the Japanese FFIX OST and also on the US FF S Generation CD album released by Tokyopop.

Hopefully this has helped. :)

I would dig into the Falcom discography, since they have released numerous vocal albums, as well as including vocal tracks on numerous other albums. Falcom is probably the most vocal heavy of the bigger game companies. The Ys Perfect Collections (I-III) and the Sorcerian Perfect Collections have great vocal tracks. My personal favorite from Falcom is "Way of Life" from LoH: Zero no Kiseki.

Check out the following:

Wish from Shenmue
Lost in Thoughts All Alone from Fire Emblem: Fates
Kokoro no Kakera
Katamaresort Song from Katamri Forever
White Night Imagination from Atelier Iris: Eternal Mana