This is a tricky answer.
The PC port of the original Darksiders has a huge amount of flaws. It crashed often, until the config file was altered slightly. The achievements only track if its the first time you've accessed the game on steam (if you crash, you need to restart Steam), the pacing is pretty broken, and there is no replay value. Overall, it's a decent adventure and platforming game if it is heavily flawed. If you can get it for $10 or less you won't be too disappointed.
Darksiders II is a completely different animal. They included a bunch of RPG elements, increased the length, but installed about a billion percent more traversal. It wasn't truly a sequel to the original, more like a reboot with the same continuity. The inclusion of DLC, and the price tag that only hits reasonable on a sale, and petty crap for the DLC, makes it a harder recommendation. If you get the mission DLC and game for around $20 then you shouldn't have much to complain about.
If you're going to get one of them, go for Darksiders II. The entire story of the first is covered in a cut scene at the end of the second, and you don't miss out on a lot. If you do buy II then skip out on the armor DLC. It's all worthless after you pass a certain level.
Darksiders is not a series that bears the horror trappings. If the main characters looked less like gorillas who fell into a pool of armor bits then it would be impossible to miss the sign of it being a bland Zelda rip-off. It's hard to say, but there's nothing here that other games don't do as well or better.