Gateron KS-9 (good&cheap; PRO=pre-lubed; amazon)

• black 2.0mm/60g/linear
• red 2.0mm/45g/linear
• brown 2.0mm/55g/tactile
• blue 2.3mm/60g/click
• green 2.3mm/80g
• yellow 2.0mm/50g/linear
• white 2.0mm/35g

Cherry mx/Kailh/Logitech GX

• red: 2.0mm/45g/linear
• blue: 2.2mm/60g/click
• brown: 2.0mm/55g/tactile

Razer/Kaihl

• yellow: 1.2mm/45g/linear
• orange: 1.9mm/45g/tactile
• green: 1.9mm/50g/click

Logitech Romer-G

• linear: 1.5mm/45g
• tactile: 1.5mm/45g

Source: mechanical-keyboard.org, x-bows.com

See also: Ferris T34 open source keyboard, HandsDown layout