Fallout 3: The entire main quest made me want to smash my head into my desk several times by how everyone kept talking to me like I was a fucking idiot, and the Intelligence Dialogue Options seemed to prove it.
Fallout New Vegas: The fetch quest for the vital pieces for Lorenzo in the Brotherhood of Steel, BUT if you do it right, you can hit at least 3-5 birds (quests) with one run through those vaults, netting you some seriously huge XP, Rewards, Reputation pointers, and even likes from your Companions, making the fetching pretty worth it.
Fallout 4: Cabot's House/Ghoul in the Fridge. Fuck that and fuck Bethesderp.