Backloggery is pretty good. I maintain my collection there and on Gamespot for who knows why.
I noticed the other day that GameFAQs goes completely overboard and lets you pick options like "want to play," "played it a lot," "beaten it," and "totally beaten it," and then you can mark whether you own, plan to buy, or even that you just "have access" to a game. All of those you can select for individual editions (regular, LE, bundle, international, etc.) of a game. Way too OCD for me, but it's so insane that I had to mention it.
Looking forward to seeing the CAG 2.0 system.