Some are easy to find, some not so much.
Elfquest - portal to fantasy for a generation
Hawkworld - both the mini and the ongoing; a series about politics that isn't political.
Fables - especially the early volumes
Nexus - space opera and whimsy, starring a galactic serial killer. He's a good guy. Honest!
Swamp Thing - the very early stuff by Wein/Wrightson and the Moore run.
Ruse - clever Sherlockian pastiche
Legion of SuperHeroes - The Levitz run from the 80's, the Waid/Peyer run from the 90's. For samples: THE GREAT DARKNESS SAGA from the former, THE WHITE TRIANGLE arc from the latter.
Amethyst - the original mini. Kid friendly on the surface, real fantasy meat just below.
Suicide Squad - The Ostrander run. Definitely not the current version.
Resurrection Man - the original run. Quirky and fun. Current run promises more of the same.
Green Lantern/Green Lantern Corps - everything since Johns took over
Starman - the Robinson series
Thor - the Stracynski run
Currently available:
Mystic - If Marvel doesn't make it an ongoing they're idiots. Then again...
Journey into Mystery - Curent Thor isn't bad but Loki is waaaay more fun.
DC? Too early to tell about the Wildstorming of the DCU, which is what the "New 52" is about.
So far, I'm underwhelmed.
Three weeks in, only the titles *not* rebooting have caught my eye. GLs, Resurrection Man, LSH, Legion Lost. This month, I'm getting them all to sample. Next month I may be down to six. (Which is about right, according to Sturgeon's Law.)