We do the $18/month, 3DVD at a time plan and LOVE IT. Our local video store (the only one for 40 minutes) just stinks, and is horribly expensive ($5.50/video). We don't have TV or cable (we live in a valley, so to get literally any channels you must have cable, and the bare basic package is almost $40/month), and we both like fairly esoteric movies (Indie, foreign, short films, etc.). We've had nothing but positive experiences. We also trade DVDs with our neighbors regularly, as two of them also get netflix, which makes it even more worth it for all of us. Like Esiders, our queue is full of Britich TV shows, classics, documentaries, and weird stuff you just can't get in a small town.
We did try the library thing. The DVD rack is literally 1 shelf of about 4 feet long, and it's very censored. They will not order anything over PG, either, with the excuse that the would be liable, blah blah blah. Most of it is Christian programming, and while that's fine, it's not what I usually want to watch with some popcorn and my DH on a relaxing night at home.
For us, it's money well spent. Even if we only get 1 movie a week (we get more), we'd be paying less than the local video store (assuming we returned everything on time and had no late fees). And, with such a small selection at the local store, there's almost nothing we'd want to watch anyway.
"This isn't life in the fast lane, it's life in oncomming traffic." -Terry Pratchett