I like my Axiom panniers and rack. They are top opening and top loaders. I prefer the top opening/ loading panniers for commuting and utility riding. My wife and I have had them for 6+ years without any problems. I have also had some Ortlieb rollers and they were very nice and I am sure they would last a long time, however, they were a good bit heavier, and they just seemed to be a bit much for commuting and utility cycling. If I were going on a world tour I would probably get another pair of Ortliebs. I also have a pair of Louis Garneau panniers and they are side (suitcase style) loading. I do not like them for commuting but they do work well for small 4-5 day touring activities.
I personally do not like the "trunk" style panniers that have the smaller pannier bags that fold down. They set to high on the bicycle and can effect the "top heavy balance" of the bicycle. Proper panniers will hold more than the trunk style panniers and they hold the weight lower and help stabilize the bicycle. All of my panniers have shoulder straps so I can carry them with me if I need to.
The Ortliebs are probably the best built, and rain resistant, but they are also heavier. The Axiom's are probably second best but they are a good bit lighter, not as rain resistant, I put my things that could be damaged by rain inside water resistant plastic bags. This will keep those items safe from water, help me organize my panniers and keeps my overall weight down. The Louis Garneau panniers come with a built in rain cover and they have been effective the few times I have had to use them.
Hope that helps! Its always fun to shop for bicycle items!