Servants of the Imperium
Servants of the Imperium was a webcomic set in the Warhammer 40,000 universe, written by Rob Leigh. Originally started in 2008 as a few one-off strips based on a Dark Heresy campaign he had been involved in, it quickly launched into a deeper plot about the race for a Chaos artifact.
If that sounds like Order of the Stick, you're not far off; the two comics share a similar art style, comedic style, and plot development. Of course, SotI is far younger than OotS, and therefore far less developed and far less popular, but still fairly good.
It can be found here.
Unfortunately, the author lost interest, and ended the whole plot in a handful of pages that were more or less textdump. Arguably this is less unsatisfying than either the thing totally devolving into shit on the one hand, or just stopping updating (or worse, going into occasional-update hell) on the other, but it's a bit of a disappointment in it's own way. Mainly because it was getting rather better in general terms of plot and pacing before the abrupt cutoff.
Being warned, the getting-there is enjoyable enough. Think Sandy Mitchell's would-be Dark Heresy-branded Inquisition trilogy, that published two books, Scourge the Heretic and Innocence Proves Nothing which introduced a bunch of pretty good characters and a plot that was just ramping up but the thing just petered out because GW was no longer interested in Dark Heresy due to corporate relationships and general questions of corporate greed. Just As Planned.