I bought one used, inexpensive keyboard of each of the 4 most common switch types (see sig). I pretty much had to because there is no way to try any of these switches out in stores and it usually takes at least a week of typical use to really get a feel for a given switch anyway. Now that I have a favorite (cherry blues), I'll probably get one good board at some point, and then take a break for awhile.
There are still some switch types I haven't tried - white alps and black cherries, for example. However, based on my preferences from the 4 switch types I have tried, I can be reasonably certain that I'm not going to like black cherries. White alps might be a possibility, but it depends how much they resemble black alps, which I really don't care for.