(this works better if read with Mr. Bean's voice)
So, a lot (not to be confused with an alot) of folks seem to be having an hard time playing the game, they get crashes, very low framerates, and other performance related issues, and some seem to be looking to upgrade their PCs.
So here goes.
The two things that make the most difference are the video card and the CPU.
If you're upgrading the CPU but also have an older video card, the smart choice is getting a CPU that can replace both your old CPU and your old video card. If you're going this route, you'll want to get the AMD A10-7850K, You'll also need a motherboard, and really any with the newer FM2+ socket will work fine. If you're not sure which one to pick get the Gigabyte F2A88X-UP4.
If you already have a decent video card and are looking for a new CPU, look no further than the Intel Core i3-4360. Or, if you want to be a little better prepared for the future, you can go for the Intel Core i5-4690K. For the motherboard, any with the Z97 socket works, so it's only a matter of how much money you want to spend. If you're on a budget, get the MSI Z97 Guard-Pro.
And that's it for CPUs, so let's move along to the video cards.
Unlike CPUs, where there is a point where more CPU power doesn't really improve games, for video cards it does, so it all depends on how much you want to spend.
If you're on a tight budget, go for the Radeon R7 260X. This probably will only let you play DFC on "low", if you're going 1080p.
Going up a bit, there's the Radeon R7 265. This should let you go up to "medium".
Still a bit further up, the choice is the Radeon R9 280. This one should let you go up to "high".
There are other, more expensive video cards. If money isn't a problem, look them up.
And that's it.
Oh, do look around for better prices!
And for reference, all the articles: