What are the most important comics to read to get a good overview of the Marvel Universe?

I realize it’s a lot, I’m just curious what all I should be reading if I want to learn more of the universe. I’ll deal with Ultimate and other alternate universes after the main. If there’s any sort of order I should read them in, that would be appreciated too.
Answers like the first are not very helpful. I do not mean to be rude, just specifying that I’m looking for history without needing to read all the golden/silver age of every character. A list of spoilers from the last year is actually quite counterproductive.