The Last Guardian

I forgot about Red Dead and the Mass Effect series. Never played those either. Now that I think about it there are a lot of good video game series that I never played.

Final Fantasy VII. I had it as a kid but was never smart enough to get past the first disc. Tried starting it up a few times over the years, once even getting pretty far before dropping it long enough that I knew I wouldn't be going back to that playthrough. I'm starting to come to terms with the fact that I'll never play it all the way through, and even if I do I won't appreciate it as much as someone who beat it and really experienced how revolutionary it was.

Gears of War and Forza.

Final Fantasy 7.

Yep me too I was addicted to uc2 and uc3 multiplayer for FIVE years in total. I missed on a lot of games but I am catching up on a lot of games thanks to ps+. 

Knights of the Old Republic. I have it on Steam, but the game just looks too dated for me to get into. I feel like I would have really enjoyed it if I played it closer to its release.

Chrono Trigger
Xenogears
and pretty much everything on PS3.

Any games I might have missed in the past gens I'm playing every now and then on my PC or android device. The list includes but is not limited to:
- Skyward Sword
- Minish Cap
- Twilight Princess
- Shadow of the Colossus
- FFX
- Pikmin 2
- Secret of Mana
- Dawn of Mana
- MarioKart Wii
- Revenant Wings
- Tactics Advance
- Grimoire of the Rift

Deus Ex.