Green Minion :
For Cooler Master Quick Fire Pro What Do you think is the best Cherry Mx Blue or Red or Brown?
This question is REALLY SUBJECTIVE.
Which is why I always recommend people to go down to some shops that allows you to try the different keys.
In short, the MX Blue is the loudest among the 3 and also it needs more force to actuate the key (55g). There's also a distinct click when you are pressing the key down midway that tells you that the key has already been actuated. These are generally better for typing.
The MX Red, the one I'm using now, is the lightest (45g) and there's no distinct actuation point. So the sound is minimal and you wouldn't know if the keys have actuated or not. However, you can multi tap these keys very quickly if you are used to them. I got these keys because I play a rhythm game that requires spamming of several keys.
The MX Brown are somewhat in between the two. It has 45g actuation force. But like the MX Blue, there is a distinct click that tells you that you have activated the key. I have not used this switch so I can't really comment a lot on it.
For more information, http://www.overclock.net/t/491752/mechanical-keyboard-guide#post_6009482.
Feel free to ask more questions.