While there are no adventure paths as such, there are some larger adventures intended to be run over the course of many sessions. The
DCC conversion of The Dark Tower is intended to, over the course of several months, take PCs from 3rd/4th level to at least 6th and probably beyond. And this can be expanded by starting with the 2nd level lead-in adventure, By Mitra’s Bones, Meet Thy Doom!, and expanded in the other direction with the Chosen Sons of Set.
Coming up is the
DCC conversion of Caverns of Thracia which takes characters from level 1 to 5 over the course of a potentially year-long campaign. I believe they've added a lead-in funnel, and expanded the adventure out in various ways as well. I wouldn't be surprised to see parties go past level 5 by the end.
Megadungeons are just one option. I like to start with an evocative setting (such as
Lankhmar,
Dying Earth,
Hubris, or
Tales From the Fallen Empire), workshop a starting premise with the players, sprinkle in a few appropriate modules here and there for PCs to stumble or get hooked into, and just follow my nose from there. Hubis with its absurd number of random tables is great for this style of play, but really all of these settings just ooze with opportunity for adventure.
Ooh! I should also mention the
Sunken City Omnibus from Purple Sorcerer Games, a great set of four adventures in one volume from a stellar 3rd-party publisher. I should also mention the vast array of largely excellent 3PP books for DCC.
Overall, I'd have to say I've found DCC excellent for long-term play. Funnels get a lot of attention, mostly because they're fun and they're ideal for convention play. But many aspects of the game only really sing when the campaign really gets going.