I've personally added webcomics to my nightly routine, right before shave, shower, and shit. At this point it's:
Sluggy Freelance - Yeah, yeah. Reading Sluggy at this point is just like being married to the thing; we're both constantly angry and cheating on each other, and the bitch ain't getting any prettier, but frankly we've been together for so long that I just can't imagine it not being there every night to let me know the world's still stable.
8-Bit Theater - If Sluggy's my wife, 8BT is my evil harpy of an ex who I can't seem to stop seeing even though I completely hate her guts.
Schlock Mercenary - Easily the most improved artwork in a webcomic ever, while the writing has always been consistently intelligent and entertaining. Your daily fix of soft-boiled sci-fi and hard-boiled wit.
The Adventures of Doctor McNinja - Currently my favorite of the lot. When it's not consistently funny, it's consistently awesome. For some reason I can never convince anybody besides Thad of this, though.
Achewood - The only current strip-format comic, digital or otherwise, with any sort of cultural value whatsoever... which the creator himself thinks is a ridiculous idea and constantly makes fun of. People I tend to make friends with always seem to already be reading it.
Looking for Group - I haven't played WoW in over a year, but the beauty of LFG is that it doesn't require in depth knowledge of who Nerz'ghul is or anything like that. It's content to simply spend its time skewering the various archetypes and stereotypes that WoW presents. I do wish Sohmer would get a writer or something, though, because sometimes he misses something and then suddenly the plot makes no sense.
Maxwell the Demon - Your standard "Devil in a business suit" tale, written by a woman, which for some reason makes it so much the more better. Beautifully drawn, too. Most of the time.
The Non-Adventures of Wonderella - Deconstructing superheroines. Yep yep.
Misfile - I really ought to stop reading this crap, but it always seems about a week away from a teenage lesbian sex scene. Like Kryptonite, I am powerless to resist.
Penny Arcade - I keep up with PA, but I don't read it with any regularity and I usually don't read the news posts much unless it's necessary to understand the strip (which it often is, god damn it). Tycho and Gabe understand their own importance in the gamer community and they tend to be a little bit irritating about it, whether they mean to or not.
There's also a smattering of strips that I'll check in on every few months and read the archives of, or which are probably still good and I don't read them anymore. This list is probably more than enough for now, though.