It's totally personal. I've tried several Brooks and a bunch of others, including a half-dozen $5 old Italian ones from the Madison Swap. In order what I like:

Selle AnAtomica (running three of them now)
Brooks B17 Imperial
Specialized Toupe 143
Specialized Alias 143
Brooks B17
Brooks Team Professional
Specialized BG
Specialized Toupe 135
E3 Form
all the rest

I got a bunch for sale if anyone wants to buy a "test kit"