Blockbuster is another good option for about the same prices. I only do one out at a time, since my GF has Netflix, for $8.99. If there is a BD-carrying Blockbuster in your area, for a few dollars more you can exchange in-store for a BD movie off the shelf. When I did that, I got unlimited 1-at-time via mail plus two in-store per month for $13/mo.
I'd much rather rent because most movies I only watch once before they start running them over-and-over on HBO, or later, regular TV.