I've been keeping up with IGN's top 100 RPGS of all time and Mass Effect 2 shows up. The slight description and reasoning for being listed mentions that it neither does third-person shooting nor role-playing tropes in particularly great ways. However, it combines these elements with a story-driven experience in a fairly rich universe. The latter made me keep playing. If I could avoid combat I usually did.
Anyways more to my intention of the thread. Games that you didn't give a fair shot because of your own limitations. I can think of one from the times I was waiting in between Final Fantasies on the PSX. Persona 2: Eternal Punishment. I read about this game and loved the idea of having rich characters that did not fit neatly into a cliche. The story was a bit morose but, humorous, reminding me of the best darkly comedic, horror films. Of course, being an RPG, it had all the familiar elements of anything in the genre but, with its own twists. I simply refused to be taken out of my comfort zone with the random encounters. I wanted the encounters to play like Final Fantasies or Suikodens or something that is traditional but, not necessarily bland. I tried 3 times to play the game but, never got more than 3 hours into it. It is a shame on my part.