My front panniers are Nashbar knockoffs of Ortliebs; the current model looks like this. I've had mine for nearly four years and about 3,000 miles, and they don't show much wear at all. Advantages: Cheap, durable, waterproof -- still no leaks. Disadvantages: You've got to roll the top of the bag, Velcro it, and buckle the lid over it every time you close it (and backwards to open it). But did I mention they're waterproof? I regret that mine are all black -- I like bright, reflective colors for safety. Anyway, these work fine for me.

I have a mismatched pair of rear panniers right now. They're OK (one of them has been OK for nineteen years!), but I'll not discuss them here.