This topic has certainly been talked about at lengths, you'll find the threads in one of these subforums. I use the hose only, wash and dry. Then I let the bike warm up real good, take it for a spin around the block, lube the chain and tuck it into bed lol.
Keep the pressure washer away unless you are super careful and spread the spray out so it's not so concentrated. They will do more damage in the long run then good.