The Arkel GT-54 touring panniers are my favorite touring bags for any long distance ride. They are made of high quality materials and the company is friendly and offers a limited life-time warranty on all their products.
I've used these panniers for multiple touring rides and they have always worked great for me. I love how the bags have many separate pockets and pouches; this makes it easy to find what you need without having to look through one big pocket. These bags are also fairly water-resistant although if there is a downpour it is best to use the additional waterproof covers that Arkel sells. The bags also look great!
I love how much space these bags have; I've never had a problem fitting my gear into the 3300 cubic inch space. They also don't weigh very much, and even with full load the bags handle very well. I highly recommend these panniers to anyone looking for high quality gear for long distance bicycle riding.