Mechanical keyboards are pretty specific to the person, there's linear vs. tactile, different actuation etc.
Currently, I'm using a Hexgears X3 TKL with Gold Kailh speed switches (tacticle). One of the best keyboards in my arsenal; I code for a living, so I'm constantly on it. Got mine off Amazon.
You can also just buy a keyboard base, choose some switches you like and build your own. With hotswap bases, the keys simply plug in and out. I have an ergonomic base (Alice layout) I do this with.