I've been on two more recently, Blue Tornado at Gardaland and Vampire at Walibi Belgium.
They were both pretty putrid, but far from the worst.
I think the best one (from what I can remember) is the one at Superland in Israel. Well, I remember being suprised by how smooth it was, anyway.
Traumi was pretty smooth at Southport, although as Infusion it seemed rougher.
Notable rough ones (no order):
Kong @ SFDK
El Condor @ Walibi World
Flight Deck @ Canadas Wonderland
Mind Eraser @ SFA
It's impossible to rank, as you can't remember every detail of a ride, and there are sometimes years between riding them. But, these ones stick in my mind as being particularly foul.