This one's slow-ish with an acoustic guitar backing, it's the most realistic tuning I've ever heard so far. Heck, a normal person probably wouldn't notice this was a vocaloid singing.
Aaaahhhh, this one is a classic Yukari song >~<
The electric guitar is really great but the somewhat monotonous yet somehow catchy vocals is just what sells it~
While we're at it, you should really follow kyaami for great vocaloid covers c: