Sluggy

Sluggy

Very, very, very long-running webcomic -
a bit of a minor legend in its own right.
(Characters from it have cameoed in published novels.)
Started August 25, 1997, and it's been running a strip
(or 'filler') day of every week of every month of every YEAR since.
Creator: Pete Abrams.

Honestly, this is one to read on a rainy day -
or a rainy week. There's a lot of continuity that
makes it tricky to jump in at the current strip,
and ~3500 strips aren't something to scoff at.
Though Abrams has his ups and downs over the has his ups and downs over the 10 years he's been drawing the strip, the thing as a whole is quite
good.