I did hit the level cap while playing 3 and it killed my enjoyment of the game. It's not like the story or gameplay, removed from the persistent growth of my character, held any particular charm. It's worth noting that this occurred after exploring 80% of the wasteland but not getting too much further than the Lincoln memorial portion of the main story. However, this could be the foundation of a strong argument for replayability. There were a ton of things I never saw: the giant robot, most of the SW portion of the map, Ten Penny Towers, Dogmeat, any of the human companions besides the dude in Megaton who demands too much money, most of the DLC options, etc. However, I did see Little Lamplight and Operation Anchorage -- two elements so sorely out of synch with what I considered "Fallout" that I wasn't sad to let the rest go ("dinged" to the cap and I was done). I even purchased The Pitt but never cared enough to give it a go (I was playing on the Xbox so my FO3 was vanilla; I purchased the boxed version of the Pitt and Anchorage used so I got my money's worth). New Vegas, however, seems interesting enough (and reactive enough) to warrant a second playthrough. *eDit: says the guy who hasn't opened his copy and is hoping the Bethesda tropes don't make him vomit. p.s. Does it still play that same annoying music from Fallout 3 when you die?