1: syudou - Call Boy

syudou 👍 but I think I prefer the vocal version for this one. The background vocals don't really fit the Vocaloid tuning in my opinion.

2: TOOBOE - utage.

TOOBOE is also consistently really good. While listening to them back-to-back I've noticed how similar his and syudou's styles are, which might explain why I like them both a lot.

3: Deco*27 - Ghost Rule

It's a classic for a reason. Very good modern Vocarock.

4: sasakure.UK - chimera

A hybrid Vocaloid/Singer song. The mixing is very unique in this one, because it's done in a way that you (or rather, I) cannot distinguish between the two voices, creating a new "voice" that's somewhere between the two. I really like it, though. Sounds very unique, but the two voices mix very well together.
The Annabel version linked in the description is really good too, and I think I still prefer that one, despite my compliments for this version.

5: Kikuo - Tunnel Adventure

Among the best Kikuo songs in my opinion. I like it when he does slower, more calm songs than his usual more frantic stuff. He shines in both, but these kind of songs sadly don't get as much attention as his other stuff. It's been steadily getting more common over the years though, so let's the what his next album will have in store for us.

I noticed my last post only got one upvote. How did that happen? Did none of you see it or was it just bad? Anyways, it explains the mod stuff (as far as I could) so go read that if you're wondering about it