In recent memory, I'd put it at a tie between Fallout 3 and Elder Scrolls: Oblivion.
Fallout 3 - Oh, you didn't opt to kill yourself in the radiation well? WELL THEN YOU ARE A SELFISH ASSHOLE AND A TERRIBLE PERSON FOR NOT FOLLOWING IN YOUR FATHER'S FOOTSTEPS OF SELF-SACRIFICE. Oh, you have a buddy who is immune to radiation and can do the thing without consequence, everybody wins? NO YOU ARE STILL A SELFISH ASSHOLE AND TERRIBLE PERSON FOR NOT FOLLOWING IN YOUR FATHER'S FOOTSTEPS OF SELF-SACRIFICE, DESPITE THE FACT THAT IT WOULD BE COMPLETELY UNNECESSARY AND A WASTE OF LIFE. (P.S. You're a jerk)
Elder Scrolls: Oblivion - Oh man there sure is this big conflict coming up. Hey, thanks for running this escort quest to get this NPC to a temple. Wow, look at that big daedra lord. Bet that would make for an awesome boss fight! WELL TOO BAD. Sit back, junior. Captain NPC's got this shit, you don't even get to participate. That sure was a heroic chaperone job you did there, give yourself a pat on the back. (P.S. You're irrelevant.)