I'm pretty laid back. I give a lot of anime 4-5 stars if I enjoyed it at the time. I've found that I tend to go back and re-rate them when I come across a REALLY good one that puts the others into perspective/to shame. Haha
Also, I try not to rate a show if I've only seen one or two episodes. I'll usually try to wait until I've seen at least 10 before passing judgment.