Tried for how long?
? - a terminal keyboard that was really, really nice, can't remember what it was now
? - another terminal keyboard that was not as nice, some of the keys stuck a bit (on lots of different terminals)
Televideo 9xx terminal - kinda ok, but old, reasonable feel for its age
IBM probably beamspring - extremely heavy, extremely loud, connected to an old, heavy IBM terminal of questionable origin
NEC APC H4100E - one of my all time favourite keyboards, and one that I learned many of my programming skills using
VZ200 chicklet - no comment
Commodore 64 - a classic, but I seem to recall I didn't like the feel much
System 80 - ok, kinda plain, another one that I learned a lot of my programming skills using
Apple ][ - ok, can't remember much about it now
Apple ][c - seemed a bit small, although that might have just been the computer size back in the day
? - some really old HP terminal, very old keyboard, good feel for its age
HP 700/96 terminal - sticky keys, still got one of those terminals at work
VT220 terminal - nice big keyboard, but rubber dome, average
VT420 terminal - see VT220
Sun type 5 - nice square keys, good colours, keys were a bit sticky though
Link terminal - MX blacks - not vintage (according to the logos on the switches), but buttery smooth, still got that one and still use it
Apple white keyboard - broken space bar, so I didn't like it from the start, collected dirt inside the transparent case
Apple black keyboard - better than the white one, but very mushy
Apple aluminium keyboard - o for scissor switches, but one of the little bastards keep giving me little electric shocks
Ducky Shine 1 - MX blues, red backlighting, my first modern mechanical keyboard, very nice
Ducky Shine 1 - MX blues, green backlighting, see above, the green backlighting is nice
Ducky Shine 3 Yellow Edition - MX blacks, orange backlighting, feels gritty, the backlighting is orange to me, not yellow, disappoint, using it at work atm
QFR - MX black, nice and smooth, branded case, but doesn't bother me
QFS - MX green, fantastic, good clicky action, unbranded black case
CM Trigger - MX blues, broken (bought for repair or parts, still on my list of things to do, kinda works sometimes)
HHKB 2 Pro, white - most excellent, nice layout, very thock
Model M full size - * 2 pretty much the same, good solid feel, one is a bit inconsistent (rivets?)
Model M SSK - * 2 pretty much the same, Esc doesn't click on one, modifiers stick a bit on the other, good keyboards (using one to type this)
KeyCool 87 - MX red, whiter than white case and PBT keycaps, looks great, switches way too soft
IBM something rubber dome - good feel for a RD keyboard, managed to find a nib one somewhere, then threw it out
innumerable Dell rubber dome keyboard - meh
innumerable other generic rubber dome keyboard, some average, some bad, some absolutely atrocious
iPad onscreen keyboard - very light feel, no tactile feedback, reasonably spaces keys though, usable in an emergency
Digital something - rubber dome keyboard, but almost feels like a cross between Thorpe and MX red, very good as far as RD keyboards go (SO using it now)
CODE TKL - MX clear, newest keyboard, the switches are about the first ones I don't bottom out all the time, liking it so far!
There's probably a few more, but as far as memorable (and not so memorable) keyboards go, that's most of them. I'll update this if I can remember any more of them.
Edit 08-Sep-2015: added the CODE TKL MX clear
