If you like metal, 80's B horror movies, and fantasy, you'll like this!
I know it has a very focused target audience, but I really enjoyed it. I don't understand why movies like Frozen are 100% recommended by critics when people like me would never watch sappy cartoons like that. Why does a movie for kids get a top rating but a movie for stoner metal nerds get panned? Knights of Badassdom doesn't have universal appeal, but if you like Black Sabbath and Evil Dead and Dragons, I don't see how you could not enjoy this movie.
It definitely misses the mark on some of the pacing and characterization it was going for and it could have been A LOT better. I wouldn't call it a classic even for me, the target audience. But all it's faults kind of add to that crappy B movie 80's appeal of the whole thing, and you couldn't have gotten a better cast if you tried. I'm not sure if I'll watch it again, but if you are part of the target audience, you'll probably enjoy yourself, don't listen to the bad reviews.