Goblin Quest, by Jim C. Hines
If you're tired of waiting for The Order of the Stick to update, why not turn to Jim C. Hines' goblin series?
They're not exactly the same thing, as Goblin Quest leaves the fourth wall intact. There are no references to PCs, levels, or dice rolls. The story does, however, take place in a classically D&D-style world, and sets out to skewer its foibles. They're likely to appeal to the same kind of reader.
What makes Goblin Quest work is that Hines has the good sense not to hang his entire story on the jokes alone. Humorous fiction is fine and well, but if humour is all it's got, then it soon starts feeling flimsy. Along with the funny, this series has a keen eye for the logical and ethical problems that accompany the adventure-fantasy subgenre. The result is a good balance, where the material gives the humour a foundation to stand on, and the humour keeps the material from sounding preachy.
I also like that Hines sticks to his guns where his main character is concerned. Jig is a runty, sub-standard goblin, picked on by his fellows and spat upon by the adventurers who take him prisoner as their guide (and canary) through the dungeon they're exploring; when the story ends, he's still pretty much the same runty little goblin he was to begin with. Which is not the same thing as saying he doesn't grow as a character; he does. But his growth doesn't involve casting off his basic nature. It's tempting, in a story like this, to have your cowardly, amoral character turn into a hero by the end. Hines manages to have Jig prevail over his obstacles without ever abandoning the key goblin virtues of cowardice, back-stabbing, and generalized grossness. The result is not only a more believable character, but a lot of solutions to problems that break out of the standard patterns we expect in this kind of story.
What Jig has going for him is cleverness and an inquisitive mind. Like many disenfranchised individuals, he's able to see the shortcomings of goblins and their society with a clearer eye, and to cast off some of the more limiting patterns of thought. I've only just started the sequel, Goblin Hero, and haven't yet picked up Goblin War, the concluding book of the trilogy, so all I know about the rest of the series comes from the bits and hints Hines has dropped on his LJ (jimhines, as you would expect). I have every confidence, though, that he's held fast to these two strengths: the pairing of humour with substance, and the determination to make his goblins act like goblins, not noble human heroes in warty blue skin.