The weapons: FO2 had some goofy ones in itself. The Holy Hand Grenade, Phaser, Solar Scorcher and several real-world weapons that were severely out of place due to the time period. The Desert Eagle, Pancor Jackhammer, and so on.
NPCs: Am I the only one that remembers the legion of NPCs that had around five rotating lines total that'd scroll over their head when you clicked on them? FO3 just has less of those standing around, that's all.
As far as the realism complaints, Bethesda's just going for Rule of Cool over uber-realistic. If FO3 (or 1, or 2 for that matter) were too realistic, they wouldn't have been so fun.