My Rating Process -
I normally start rating an album after 1 or 2 full listens, if I make it that far. Over time, the more I listen to an album, the more I realize I enjoy it, so albums usually rise over time, or stay put.

.5 - Worst of the worst.

1 - Doesn't strike my fancy at all. Not worth another listen.

1.5 - Not bad. Again, usually not worth another listen, but I probably wouldn't mind.

2 - This is a good album. Worth spending more time on.

2.5 - An Excellent Album. Usually an album I re-queue immediately. Deserves many more listens.

3.0 - An album that holds it's value after repeated listens. Usually Album of the Year candidate.

Anything above a 3 means I have been listening to it for months or years, and still enjoy it. The more stars, the more enjoyment and value it has brought to my life.