I've made a playlist for VOCALOID/UTAU/etc. songs and covers. You can find it here.
Unfortunately, I don't have a lot of time to look for songs so I'm open for suggestions!
Post original songs that you like here and I'll add them to the playlist. The only exceptions: no Miku, Rin, Gumi songs!! There are plenty of them in the playlist already. Group songs including them are okay though!