That is an astounding list... I tend not to buy as many games, and I "only" have 4 active systems to buy for right now. I guess I tend to get a game and keep playing that one game until I either finish it or I decide its not worth finishing (not my taste, not enjoyable, etc). I think my ratio is pretty decent - I finish maybe 8 out of 10 games and sell the ones I didn't enjoy back to the store quickly enough to get a decent/so-so amount of money back for the next game. Right now my backlog is "only":
Last of Us
Beyond Two Souls
No Ni Kumi
(and the PS3 backlog is only there because I bought a PS3 about 2 months ago).
Currently playing Disgaea 4 on the Vita. Hubby is playing Disgaea D2 on the PS3.