If you are made of paper then use capacitive switches. If you are made of cardboard then use Cherry blues. If you are made of iron then use buckling springs. This is a general guide however I have found that it is useful on many occasions.
I like the sensation of typing on buckling springs, the satisfying click is nice to linger over and the sound is most sublime. However when I am typing I actually prefer a slightly lighter touch and on a practical level I am somewhat perturbed that my typing can be most definitely heard through more than one wall. I am currently typing on Cherry blues and am seeking to purchase a board with browns in (Kinesis). I like the capacitive switches in my HHKB however after having paid a lot of money for it I am too scared to use it; it feels good though.
I think the point to be taken from this post is that it is difficult to get a handle of the feeling of a switch until you really try it out. For a lot of people it is not really possible to go and do this due to the fact that most of the boards we talk about are not as readily available in a physical shop (in a lot of places) as a standard rubber dome board. For the sound you could try the audio section of this website or some video websites, however the actual feel differs from person to person discounting our abilities to convey the feeling in a sufficiently precise manner (in this context the graphs that ripster is providing are probably the best that you can do). There is also the fact that some boards might be nice to activate the keys on but not actually be that nice to type on. When I first got my Model M I thought that it was the greatest thing ever, this was because it looks stunning and just pressing each individual key slowly will get a rather lovely sensation, however I have subsequently found it not to be to my tastes for a keyboard that I plan to use on a regular basis.
tl;dr You will have to procure some boards for testing in order to get a good idea, however the feeling of pressing a buckling spring is rather nice. Also get a Model M that is in reasonable condition and then very softly run your fingers over the keys, you feel a wonderful texture that makes you aware that you are in possession of a good board.