First a disclaimer....I have NO IDEA how accurate this is and doubt it is very accurate. But it might be able to be used as a barrometer of some sort.
http://www.hostcount.com/main.htm
Just some of the hosts off the top of my head that are around here have the follwoing ranking out of 30,000+ co's
natianal-net.com 57
candidhosting.com 128
isprime.com 148
phatservers.com 241
jupiterhosting.com 751
webair.com 112