I started with the usual Marvel/DC but only really started collecting in my early teens with Conan's Savage Sword stuff, alongside 2000AD, till around my mid-teens.
Stopped reading comics altogether till my early 20s, when I got into Love and Rockets, Hate, Yummy Fur, Eightball, etc.
Stopped again around my mid 20s until I started reading graphic novel reissues of Sandman in my early 30s and other occasional graphic novels like From Hell.
Got heavily into Grant Morrison for a while, stuff like The Invisibles. And I loved what he did with Superman.
Back to Conan again, about 5 years ago but only in graphic novel form. I still keep up with those.
As far as single issues go, I started buying Batman this year, with the Re-Birth, and I'm keeping up with that - although I'm sort of regretting the commitment I've kind of forced on myself by starting at #1.