Best keyboards: ALPS keyboard as fitted to late Model 1s, all Model IIIs, early Model 4s, and most model 4Ds. Great to type on and put up with the rigors of game playing, and now 30 years after the fact, easy to repair. I wrote many university papers on these keyboards and they never missed a beat. In fact if you keep using these keyboards they seem to live forever. Its only when the computer it put into storage for years or decades that when you re-start the computer some of the keys don't work.
Good keyboards: Tandy 1000 series (early), Tandy 2000 and Model 4P all seem to use the same key switches and last pretty well. The action on these keys changes over time they have a nice light feel when new but as they age they seem to get a bit harder to press. Don't know if they are repairable, never had to repair one.
Model II/12/16/B/6000 keyboards: never owned one long enough to comment but I thought the Model II keyboard felt pretty good but anecdotal evidence seems to imply that all the keys foam rubbers wear out and are an arduous job to replace.
Crappy-but-usable keyboards: Coco 2, Coco 3, TRS-80 Model 1 (early), Model 4 (gate array), some 4Ds. These (except the M1 early kb) are all shallow membrane action keyboards, virtually impossible to repair - and again are not very forgiving when put into storage. The early M1 keyboard is usually OK but exhibits kkeybouncce.
Completely useless keyboards: Coco 1, MC-10, all pocket computers.
Computers I haven't mentioned because I have no real world experience with: Model 100-102-200, Tandy 1000s after the original series, 2500s, 600s, 1400s.
Hope this helps,
Ian.