Depends if you like a light or heavy keypress, the "actuation force".
Check if you like that click sound you get with Blues or not (easy just youtube for a sound sample of typing on them)
Linear swiches press all the way down and you don't feel the actuation point (the point where the keypress is registered)
Tactile switches you can feel the actuation point about half way or more down pressing a key (on my browns when you reach the actuation point it feels like a little bump because the force gets heavier after that point) you can type without bottoming out if you have tactile keys.
LASTLY consider the type of lettering on the keycaps; some keyboards use double shot keycaps, printed, laser, stickers, all with advantages and disadvantages.
Common switches are Black which is linear but heavy, Reds which are lighter Blacks, Browns which are light and tactile, Blues which click at the actuation point are tactile and heavy, Greens are pretty heavy i think the heaviest switch and are linear.
This page breaks down all the common key switches for you,
http://www.keyboardco.com/blog/index.php/2012/12/an-introduction-to-cherry-mx-mechanical-switches/
I say Reds and Browns for gaming. Never used Greens but apparently they are very weighty so fatigue easily.
Razor i would avoid, i don't know if their Blackwidow has quality issues now but it DID have at release plus most of their gear is just tacky plastic affairs "gamer" type crap. Some Corsairs had premature LED death, where they die within a few months. Coolermasters 2015 boards are apparently a bit shit.
Really good manufacturers are in no particular order...
- DAS
- ROCCAT
- Q PAD
- Filco
- Ducky
- Cherry own brand
- Coolermaster before 2015
- Zowie (which i use) are built like tanks but the keys are laser etched so will fade away however the lettering will come back if you clean them (isopropyl or something), pain in the ass but built well.
- Novatouch
- Matais
- OZONE
- Corsair (okay boards, i think back when they didn't have so many varieties they made better boards but their okay if the price is right and your LEDs don't crap out)
Can't think of any others at the moment bar ROSEWILL in America and i don't know enough about that to say good or bad.
Other tips are, if a board is Otaku it means it has blank key caps and if a board is tenkeyless it lacks a number pad.