It's between buckling spring and a resonant blue Alps board. These two are the most fun noisemakers. This is the sort of sound I got from my Tulip ATK 030244 blue Alps board:
http://www.youtube.com/watch?v=PDMurngkHdg
(I've tried to record it, but I don't have any equipment that can capture the sound properly.)
I started transplanting the switch middles/uppers into a Dell AT102W and the sound isn't as resonant, and the switches don't feel as good. There's something in the Tulip that gives it a deep reverb. (I'm suspecting that the change in feel between blue and white/orange and salmon is down to a difference in the metal used by the actuator leaf, but I won't be sure until I've got around to swapping one of those, too.)
Since obtaining a blue Alps board is difficult enough to begin with, let alone one that's got an audiophile plate mounting, you're going to want to go buckling spring: easily available, with great sound guaranteed. IBM Model M keyboards have a distinctly more twangy sound than Unicomp boards, which have a dry sound more like a manual typewriter, but they're both great, and they are LOUD. A buckling spring keyboard is the best one on earth if you want something that makes a lot of noise. (Great one to give to your kids, especially considering that they're very robust and, if you have two-piece caps, easy to clean.)