I have a Delta Sherpa rack on my LHT. I love these racks but I don't see other people using them much. They sell for around $40 but I keep finding them in the clearance bin at REI for $10. So I keep picking them up. My commuter bikes have them too.

Mine has worked well for our short tours. It's rated for 60lbs. I carry about 25lbs on my rear rack.

I have plenty of panniers, Jandd panniers for touring and very old REI Novara panniers for commuting. But if I needed panniers I think the Nashbar panniers look like a good deal when they are on sale (frequently) for $20-30. They have a lot of good reviews on the nashbar website.