Halo.

Look, I'm not saying it's a bad game or you're a bad person for liking it, but man, I have never been able to see the appeal. As someone who has played a lot of shooters (mostly PC) and read a lot of sci-fi, I find it exceptionally mid. And I'm not really fan of the militaristic reverence vibe it's got going on like .. bleh. Does it actually criticize this more as the series goes on or is it really just all oorah? I also kind of blame it for the trends of vehicle segments and only holding two weapons that leaked into other FPSes at the time (looking at you Bioshock Infinite - WTF), although I do admit that's more of a petty, personal point. I respect that it pushed FPSes and online multiplayer forward on consoles, but when people tell me it's their favorite game with one of the best storylines ever I'm like, "But have you played any other games?"

I used to work in a game store back when Halo 3 released and I was a much more fervent hater back then, I decided I was gonna play the original Marathon games so I could be a hipster snob and hate on them, too. Actually ended up really loving them, though they're only loosely related, I think they had a lot more going on stylistically and story-wise even though the gameplay was more primitive.

I retry every few years, but never get very far. Maybe I should skip to 2 because one is so bland I get bored of it.