I've read them all, bar his newest one. Outta the two you've not read I prefer 'Boiling A Frog', don't get me wrong 'Country of the Blind' is good, but not as good, or at least in my opinon. Although, I've only read that the once so when I read it again it might grow on me.
I love all the ones I've read, so much. I've read them loadsa times each. I kept meaning to pick up a copy of his newest one that was in fopp recently but I kept forgetting and it's gone now. I'll eventually remember to get it one day though!
