I like Ortliebs too - but just to lend a bit of a contrary viewpoint, see this review from a couple who used a set of Ortliebs on an extended tour:

http://www.crazyguyonabike.com/revie...ested=0#127860

Other panniers with a reputation for being durable include Lone Peak (see Erin's other review, linked from her Ortlieb review above), Arkel, and Carradice.

Neil