Aside from a free GameFly trial sometime last year that went rather badly, I think the last time I rented was... probably three years ago. It was only because Blockbuster started doing that flat fee $20 thing where you can take two or three games out and keep swapping them and stuff.
Prior to that, who knows. Back in the good ol' SNES days, though, my dad and I racked up a Blockbuster bill in the thousands. I remember it quite clearly. For some reason, my dad asked how much we had spent there on his account. The guy behind us was like "Why don't you invest that kind of money?"
Heck, if Blockbuster was still doing that deal (are they?) and I felt like a pirate, I could have their entire PS2 library on my HDD in a week. Guess that's why Sony really hates HDLoader.
But I'm not going to that and I don't suggest any of you do either.