My rating system as of now:

★ — Hated it. Would absolutely refuse to watch again.
★★ — Would hesitantly watch again, but remains somewhat forgettable.
★★★ — Liked it, but wouldn’t mind never seeing again.
★★★★ — Would recommend to others.
★★★★★ — Can easily see the importance of the film and/or thoroughly enjoyed and can’t stop yapping about.

See more involved reviews of mine here:
http://lightwisdom.tumblr.com
http://letterboxd.com/lightwisdom/