5. The Suicide Mission - Mass Effect 2
Chances are you aren't going to journey through close to 100 hours of any Mass Effect just to replay a particular section, however with the fate of your entire crew hanging on every moment of the final stretch of part two, getting them all through in one piece momentarily transcended that. Remember that this was in a time where the mentioning of Mass Effect didn't conjure up imagery of spectrally-tinged little boys doing away with entire weeks of playtime at the last second, instead the series' reputation was at an all-time high. As critics and fans alike slowly burrowed into this final mission and emerged in many different states, the general outcry came back "Make sure you save beforehand!" This lead to thousands of us refusing to accept something like Mordin Solus biting the bullet at the last second - instead reloading, thumbing through a FAQ to see how best to keep his' skin on and having another go until everyone made it home safe.