Maximum Carnage: What made me fall in love with Spider Man and artist Mark Bagely. Lots of ppl say this is a mediocre story but i love it.
Secret Wars: The greatest major Marvel crossover epic imo. Fuck Civil War, it was just a vehicle to get ppl to buy way too many books to get the 'complete' story. Secret Wars is what epic adventure is all about in Marvel.
Infinity Gauntlet: Showing yet again why Thanos kicks so much ass. Wish they would do more with him.
Watchmen: I know but it really is the greatest comic ever writen. If you can find it for cheap get the Absolute edition, the big glossy pages make it look even better.
Dark Knight Returns: Probably one of the best Batman stories ever. A lot of ppl don't like it cause of Miller's art but it's a great story with he sequel taking it to a whole new lvl
Preacher: Amazing fun and raunchy comic. Full of great moments and a wonderful overall story.
Walking Dead: Great on going Zombie apocalypse story. Again some may say it;s not so good cause it never really has any ending but that's sort of the point from the get go with the story.