Famous when alive , forgot when dead.
Famous for doing something after death.
If I where to choose between these two, it would be the second one, famous for doing something after my death. It will be better to be famous after life because if you where famous during life and forgotten after death, that would be at least 1-150 years old (if you live a healthy life), that would only be that much time of fame. if you did something well and famous AFTER death then it would be better, more that 150 years of fame, but it could depend on what you did in your life. If you found out how to stop "freeze brains" then it would be at least 27.172 years of fame after death, but if you made a huge difference in life like saved the human race that that will last at least 1,389,743,007.5 years, if humanity can live that long with the pollution, killing ect. as long as the Human race lives, thats how famous you would be.