I know what you mean as well. Playing with him as a companion in the extended origins, Awakening - I liked his character. One of the rare characters I liked in that extension. I think the ending of DA:2 is mostly the reason I don't play it much. It seems no matter what you succeed with, you lose everything.. even both factions Templars and Mages. Although, it led into the epic Inquisition.
I think my mouth fell open three times in DA:2, maybe that is what kept me interested since the conversations, limited places to visit, and side-plots were a bit blah. The Anders one was a big one... even if I saw it coming with him.. I didn't think he would have done THAT. I have to stab him between his shoulder blades every time.. I think he killed the only innocent political/religious person, or maybe I just liked how she rebuked Orsino and Knight Commander Meredith. Also, the way she always seemed to know what was going on... and wanted to see how it would play out.