Daytripper is amazing.
I quite liked the original Elfquest.
Fun Home is really good.
Planetary is a fascinating exploration of superhero/scifi tropes, but works best if you know the references.
Transmetropolitan is really good, but not everyone’s cup of tea.
Sandman is epic, but start w/the 2nd collection & go back for part 1 if you like it. It took 8 issues for the series to find its voice. So while the first collection establishes the setting and characters, it’s a very different tone from the rest of the series.
Astro City is a great reimagining of superheroes, hopeful & standing on its own.
Oh, and Hark! A Vagrant! is a lot of fun also, especially if you like literary and historical humor. It’s a collection of unrelated comic strips rather than an ongoing story.