You can skip both CoD games without missing anything. Might be able to skip GTA as well without missing anything. 
Really? Black Ops's campaign had some really good twists while MW2 was an OK of a campaign (No where near the level of what CoD and CoD 2 were). GTA on the other hand was EPIC. Don't listen to him, all the GTAs even since 3 are all awesome games. San Andreas is no exception, but I would understand if you kinda get annoyed at all the commentary in that game... it does get stale. As for the action and what actually happens in the game, it's all top notch.
A nice idea. Some of those games are quite aged though, so they were GotY, but don't hold up all that well now a days.
Really? Games today (past 3 years) really don't compare at all to the games of the past. Half Life 2 is still better than Halo's 2-Reach, the first CoD is still the best out of the entire series, Age of Empires II is better than any RTS post 2000's (with the exception of the Total War series, but that's a slightly different RTS), and Baldur's Gate 2 is still one of the best RPGs.
Problem with most games today is that they aren't hard enough to beat on normal. Hell, even both of those CoD's on the list on Veteran aren't nearly as hard as say... Ghouls and Ghosts. I want games that make me Rage Quit, make me stop playing and do something else, reflect on what I need to do to beat it, then give it another crack.