The Intel i7-4790k is a high end 22nm Haswell based 4.1 GHz quad-core CPU. It is in Intel's K line and so is unlocked allowing for easy overclocking. It fits with the LGA 1150 socket for motherboards that feature it.
Ranked in these QuestionsQuestion Ranking
Pro Easy to find cheap components
Being that this is a Haswell chip that uses the LGA 1150 socket, it is quite easy to find cheap motherboards and cheap RAM (DDR3) to use in those motherboards. This makes a good option as it is still a powerful chip comparable to even newer ones but allows for a wide selection of compatible parts. It also is a good choice for those that are already using a LGA 1150 compatible motherboard and would just like to upgrade from a less powerful CPU.
Pro Good performance and hyperthreading
Being a quad-core CPU means that hyperthreading is available, more so than an i5 thanks to the higher clock speeds and available cache. This means that games that take advantage of hyperthreading will perform better than with a CPU that does not have many cores or is just at a lower clock speed and has less cache available. While the jump in performance is not much for games that can only utilize a single core of the CPU, it still is a jump of about 2-3 frames over an i5 of the same generation.
Con Somewhat dated
Based on the fourth generation of Intel's core architecture (Haswell) there are newer chips out there two generations ahead (6th gen Skylake). While comparing one to the next there are only slight improvements in the newer generations, but improvements all the same for close to the same price.
Con Becoming increasingly more difficult to find
More and more stores are not carrying this chip as newer generation chips are seeing their prices drop. This means it can be difficult to obtain, though there are a few places that it can still be picked up easily.