I read the first omnibus collecting Jaime Hernandez's Love and Rockets work. It's dense, clumsy, and simultaneously brilliant. It also makes it very obvious why L&R has had so much of an impact in comics. It is a stark contrast from everything else in the underground comic subculture, being a vast departure from the crosshatch heavy, scatalogical Zap wannabes of it's day. Hell, Jaime Hernandez has more in common with Steve Rude than Robert Crumb.
But what I think what makes Love and Rockets most endearing is the fact that it's a continuous soap opera. Going on from 1982 to the present day with the same characters. If you don't count autobiographical comics, this was virtually unprecedented in underground comics. This makes the comic seem a lot closer to the longer comic book runs from the Big Two, such as Wolfman's Teen Titans, Peter David's Hulk, and Chris Claremont's X Men than Eightball or Weirdo. Similar to those aforementioned runs, both Palomar and Locas can be just as convoluted, awkward, and oddly epic:
Status quo changes that will forever change the course of the book
Rocky evolution in style, tone, cast, and location
References to events from years prior
A sense of weight and legacy to the story, even if the character's don't age
These are some of the reasons why comics fans find these older superhero runs so alluring, and for me at least is why I love Love and Rockets