For a while now, well over a year, I've only really been picking up quality games at a price I like. So while I have developed a big 360 backlog, really it's full of pretty good games the vast majority of which were purchased at $20 or less.
For example, I picked Resident Evil 5 for $20 around Christmas time or thereabouts. Won't get to it for a while until after other action games like Devil May Cry 4 (bought $15) and Prince of Persia ($15). About three weeks ago I bought DiRT 2 for $20, but won't get to it until after racing games like Burnout Paradise ($18) and Project Gotham Racing 4 ($20).
Just started on my 360 RPGs with The Last Remnant ($20), and after that plan to play Infinite Undiscovery ($10), Star Ocean: The Last Hope ($20), Eternal Sonata ($20), Tales of Vesperia ($27), Lost Odyssey ($20), and then Mass Effect ($20). I'll definite add Final Fantasy XIII in the future once I can get it around $25, of course there's no rush for the time being as I wouldn't play it any time soon anyways.
Assassin's Creed II was on sale for $30 last week. I want the game but didn't pick it up, it will only get cheaper. When Bayonetta hits $20 I'll buy it.
And so on and so forth.
I'm sure I'll eventually get through all the games, at least I hope to. If I sell off these games for half of what I bought them, I think that pretty much covers the enjoyment and time I got out of them.
The only games I can see myself buying day one are Halo games, because my brother and I love them, and they provide more than my money's worth. And even then nowadays there's some kind of discount/promotion (I pre-ordered Reach on Amazon with the $20 GC).
So that's how it is for me, at least. That's why I say my 360 library is far and away my most cost-effective console game library, and quality per game per dollar it blasts anything I've had before out of the water. Just wish I could have had it this good when I was much younger, I could have enjoyed it a lot more.
I suppose it does help that I hardly ever go to the cinema or buy DVDs anymore. I'm even more selective there and with my bookshelf, I'm constantly looking at what I can take off/out more than what I can add. I want to refine it all.

