Budget - A good mechanical keyboard is in the $70+ range. You are probably aware of that
Noise - Most mechanical switches make more noise than rubber dome (what is found in most cheap office keyboards) or membrane. Some switches also produce an audible click when pressed.
Activation point - How far you have to depress a key before it activates.
Activation force & characteristic - Heavy, light, linear, tactile, etc.
Layout and % - Maybe you don’t want staggered, maybe you are looking into DVORAK and other layouts. Maybe you don’t need a numpad or 80% or 65% boards are enough for you.
Ignoring th legendary IBM Model M for now (buckling spring switches, loud, amazing to type on). Animation of mechanics
The common switches are Cherry MX and while there are a bazillion knockoffs, IMO not one of them is as good as the real deal.
Kailh is partnered with Cherry in some way, so they also have nice switches.
MassDrop had some “inconsistency” when it comes to their mechanical switches, seems to have sorted itself out though. Zeal has keyboard kits, so you could go completly custom. KBDFans also has kits, preassembled and individual parts. WASD has a wide selection of boards. Ducky also makes some nice boards.
While you could get your hands on a switch tester, there is no need to when first starting out.
Cherry MX Red’s are a safe bet.
Cherry MX Brown’s are a favourite first because of how similar they feel to rubber dome.
I am a bit of a “speed fanatic” so I am currently rocking Kailh Speed Silvers (licensed version of the Cherry MX Silvers) in a HyperX Alloy. Those may not be for everyone as carelessly placing your hand on a key will trigger it (1.2mm until activation).
I got to try some novelkeys kalith box swiches and man those are very clicky. I still prefer my unicomp if I want that tactile and want to piss everyone off at work lol
I think the cherry clones are all pretty good, in some cases preferable to the original. But they get a bad rep for being on cheaper keyboards.
Cheap light weight keyboards feel terrible no matter what switches are in them.
persoanlly for tactiles im really into topre might grab a topre board for myself as a next keyborad for the communal PC space in my future house asto not piss off my house mates
I have a varmilo capacitive switch here, and in the tester I really like it, Unfortunately they aren’t compatible with standard keyboard electronics, I might pick up a varmilo with them on, but I own so many keyboards at this point it’s hard to justify.
pretty sure you can code actuation depth deadzones, and what happens at certain depths of a key press. cant confirm though I have only had the pleasure of trying one not owning one.