I loved the Friendship/Rivalry system, and the inherent depth you could get out of the sliding scale. I loved the Cross-class combos and sought to build most of my characters around that feature after my first playthough. I loved the idea of gathering up crafting ingredients for potions and wished it was spread into other pieces of equipment, including enchanting and smithing. I loved the area in and around Kirkwall, with its history and background, of the Tevinter slavers, the Enigma of Kirkwall writings about its past, and the mystery surrounding Sundermount. I loved the role the Qunari played in the game, and was excited whenever they were involved.
But I HATED Dragon Age 2. Because my hopes were set so high that it would surpass, or at least equal, the enjoyment I had from DAO. It is not a bad game. I wouldn't even bother SAYING I hated a bad game. I would just say its garbage and go on.
DA2 had some REALLY solid gameplay ideas, some REALLY cool avenues and lore to explore, some REALLY neat ways of interacting with your companions... but its too bad that the core change to the gameplay, the combat, was dull once you got past the first ten minutes of flashy combat with zero tactics. Its too bad that instead of pursuing really juicy bits of lore that were presented, it devolved into a Mage/Templar caveman fight, with both sides being as ludicrous as the other. Its too bad that in a more unique and diverse way of talking to your companions, they didn't give us a chance to talk to them but maybe four times over the course of ten years. Its too bad that Kirkwall, an area they placed us in for the entire game, had the potential to be deep and interesting, but instead was bland and unchanging.
That's why I hate DA2. THAT'S why its my biggest disappointment. And not just for 2011. I'd say in the past five years. Its the only game I've ever pre-ordered and/or done a midnight release for that I DIDN'T feel was in any way worth it.
It took a great franchise and a brilliant world, took some really bold, interesting and promising mechanics and features, but then let the core of the game suffer and appear lifeless. That's disappointing, when all the pieces line up on paper, but the delivery just falls on its face. That's why people hate it... not for what it is, but for what it reached out and showed us it could be, but then failed to deliver on in some many respects.
/rant