One immediately springs to mind: "All we had to do was follow the damn train CJ!"
It wasn't so much that the mission in GTA: San Andreas was difficult, it was that every time you failed your NPC 'friend' Big Smoke would yell that line. The repetition and condescending nature was infuriating. All Big Smoke did was sit on the back of the bike and shoot bad guys, meanwhile you were required to not only shoot bad guys, but drive the bike and avoid oncoming trains.
Of course it did make the end of the game infinitely more satisfying, so maybe it wasn't all bad.