I want to keep playing the game after the ending... not "load up an old save". That just sounds generic.
See, I don't get this at all.
Running around exploring and doing random crap in FO3 just
before talking to Sarah Lyons to start the last mission, or running around exploring and doing random crap
after the last mission?
Completely identical in my mind. Absolutely no difference. I honestly, truly, have no comprehension of what you're saying here. :shrug:
(But, then, I'm also the type who plays RPGs over multiple times. I've made six different FO3 characters, played anywhere from 15 to 75 hours, for example. Heck, I just reinstalled Oblivion a week ago to give it another go. Played ME1 three times, ME2 twice. Many of the console RPGs, I've played twice - once to see the story without spoilers, once for the 100% completion with a hint book.)
Mass Effect 2 comes to mind as a game that pulled this off flawlessly. So it CAN be done.
As someone else said..... I loved ME2. Played it twice. But, honestly, the "play after the end" thing makes 110% no sense. No acknowledgment of your decision re: the Illusive Man's offer in the final quest, all those characters who say they'll leave after the final mission are still sticking around, etc, etc, etc. It's dumb. The ME1 ending, where it had the climix, ran the credits, The End... that worked much better.
But, then, they had to leave you able to do more stuff in ME2, since they wanted to keep selling you more DLC month after month. If people couldn't load up their old "finished" save and play another DLC, it might have been sales lost. Purely a $$$ decision, not a plot / story / gameplay one.