I haven't played Marvel Ultimate Alliance yet (I got it a couple weeks ago for my birthday, haven't had a chance to sit down and play it)
I have Metal Gear Solid 3, and while I have played it before, I haven't played it since I bought it (It's the only game that I've bought TWICE without playing my own copies of it). I rented and beat it about 2 weeks after it came out, a year later I saw it cheap, so I bought it, didn't play it. Ended up trading it in, fast forward another 2 years, and I have an itch to play the first MGS, the only real way to get MGS now adays is to get the collectors edition with all 3, so I bought that, played MGS/MGS2, skipped MGS3.
I hardly played Lost Odyssey or Blue Dragon, but those don't count here as I DID play them. Same deal with Final Fantasy Tactics Advance 2 and LoZ Minish Cap. I had Majora's Mask on my N64 and never ever played that.
I own mostly books and movies I haven't watched/read. Games i tend to play at least once.