I lean towards panniers. You can carry a ton of stuff and never have to strap a single thing on your body. There are plenty of styles, from completely utilitarian to stylish, office easy bags that look great. I got mine at the touring store - http://www.thetouringstore.com/
I use the sport packer plus bags. They lock on your rack and even with a 8lb kryptonite ny chain in one, they've never popped off.