I think that User Friendly has gone downhill in recent years, but today's comic was quite wonderful!
Which is as good excuse as any to introduce you to the webcomics that I read on a daily basis!
Alpha-Shade - an online graphic novel that starts out in a slightly anacronistic fantasy kingdom, than after nearly 100 pages, jumps forward in time to a world very much like ours. But populated with cats with mystical powers. Just read the comic, you will understand. If you have about an hour, start at the beginning (follow my link, then click on the button labelled "First" right below the comic) and get current. Otherwise, only the wonderful art will make sense to you. :) My only complaint with Alpha-Shade is that it is only updated twice a week or so, on average. Still, the art and story are top-drawer, so I am patient!
Ctrl+Alt+Del - a webcomic that mixes many of the different flavours of geekdom together, with splendid results. It is about video games, computers, and Linux, features exquisite art, more continuity than its fellow gaming comic Penny Arcade, and a large dose of The Funny. I would recommend that you start at the beginning if you have not read Ctrl+Alt+Del before, just so you can meet all of the characters and catch up on the story. If you don't feel like doing that, just jump right in with today's comic and start reading from there. The jokes still work, you will just be missing some background. Ctrl+Alt+Del gets new comics every couple of days; there does not seem to be a set schedule.
Dilbert - not really a webcomic, as it is published in pretty much every daily newspaper in the US through the miracle of syndication. However, any discussion of webcomics will mention Dilbert, because its author, Scott Adams, understood the power of the Internet back in 1996, when no-one else knew what to make of it, Bill Gates included. As such, Dilbert.com has been around for a long time, and has offered lots more than simply reprinting the daily strips. Some people say that Dilbert is getting stale; I have not seen that. I continue to read it every day, and it is rare that it fails to get at least a chuckle. Dilbert is updated daily (with the same strip that hits the newspapers--they stopped that week-long delay a few years back), but the archive only gives you a month's worth of older strips. I suppose it is Amazon to the rescue.
Foxtrot - again, not a webcomic, but Bill Amend's grasp of technology and even Linux leaves nothing to be desired. Foxtrot is consistently funny, and is updated daily. The only downside is that the archive only ponies up the previous two weeks' worth of comic strips, so I suppose you must buy the dead trees if you want to start reading Foxtrot from the beginning of time.
MegaTokyo - this used to be my favourite webcomic of them all, mainly because the artist captures the essence of living in Japan so perfectly. Unfortunately, while his art has improved (not that it was bad to start with), the comic itself has taken a noticable hit in quality in the past two years, mainly due to over-the-top melodrama. Still, it is probably worth reading. It is definitely funny, and can be quite moving at times to boot. MegaTokyo is theoretically updated every Monday, Wednesday, and Friday, but that rarely happens on any two consecutive weeks. So it might be best to read MegaTokyo every few months from the archive, so you can read more strips at once, and not lose the thread of the storyline.
Penny Arcade - the 900 pound gorilla of webcomics. Penny Arcade is hugely popular (something like four million different people hit the site every day!), and for good reason. It is about gaming, mainly the electronic variety, but Tycho has been known to roll twenties. It is also beautifully drawn and coloured. It is funny, it is witty, and it is quite profane, so readers of this site that don't dig the F-bomb should probably steer clear. If you have never heard of Penny Arcade, shame on you! Get over there right now and start reading! If you have heard of Penny Arcade, but think it is not for you because you don't game, shame on you! If you like funny stuff, get over there right now and start reading!
User Friendly - the webcomic that started this whole entry. If you are a Unix geek, head over there right now and start reading! Others should not even bother. The art has improved from those early days, but it has only gone from absolutely repulsive to just bad. The jokes are only funny to Unix geeks, and as of late, they are often not even funny to us. I blame this on the fact that the creator is Canadian.