I've found Overstock.com to be a personal favorite resource for blinds. The reasonable prices for a variety of sizes — which otherwise you might have to buy custom — are what won me over.
I avoid fabric ones because they easily can look cheap and instead stick with wooden ones. I used them in my last apartment, and in my house I have the "Ginger Bamboo Blinds." The only potential downside, which doesn't really bother me, is that they filter rather than really block out light. I have bought a set of blackout blinds for my bedroom from the site. They're less attractive, but they do their job well. During the day I just put them up or draw the curtains.
(Image: Kim Rinehimer)