In addition to the numerical score each anime gets in its review, I'm adding a second score, based purely on how much I enjoyed it, which goes as follows:
Full Moon*
So freakin' amazing that it's one of my favorites. Go buy it/watch it/give it hugs right now.
Gibbous
Really dang good, rewatchable, but not something that you're absolutely hooked on.
Half Moon
Eh. Average. You can watch it if you want, but it's not something I'd recommend for anyone.
Crescent
Pretty bad. Best if avoided.
New Moon
Ew. Ew. No. Don't even touch this piece of crap. It's just... disgusting, it's so terrible. No. Ew.
*As to not convolute my reviews with tons of "favorites", only fifteen anime can be given this rank at one time.
I'll update my old reviews to include these ratings as soon as possible, but for those who are too lazy to check:
Angel Beats: Half Moon
.hack//SIGN: Gibbous
Soul Eater: Full Moon
Ao No Exorcist: Half Moon
Deadman Wonderland: Gibbous
Death Note: Full Moon