I'll agree with Age of Empires Online, that definitely cheapened the franchise. Especially when i really enjoyed AOE3...Sadly, i really didn't get into the franchise until AOE3, and the graphics just weren't enough up to par for me to go back...
Anyway AOEO was a big disappointment for a sequel i was waiting a long time for.
Also, this probably won't be popular, but Borderlands 2 really bothered me. Which was very shocking because i totally loved the original. The problem with the game was...it was almost exactly the same as the first one, the sidequests are almost completely forgettable, and the main storyline was not at all interesting either.
That, and i really hated the over the top nature of humor. It's just so bro-tastic, and i hate that kind of stuff. Just not my type of humor. About the only thing i remember actually finding amusing was the very beginning video, and the quest with hammerlock where he referred to the creatures as "boner farts", just because it was ridiculous and unexpected.
Anyway, that game really disappointed me, and i don't think i'll be picking up the third. Just too much dead space and boredom in those games. Story is very lacking. It felt like a stripped down version of Elder Scrolls with an attempt at humor, and none of the role play elements.