Stahlsac Bonaire mesh backpack (thanks to The Kraken for that tip). Costs about 50-60 bucks and has a ton of room. Just throw everything in there and it has a built in dry sack for your towel, shirt, etc. I take a small dry box for the cards and stuff I want to stay dry that goes in the front pocket. I also carry a save a dive kit in a soft re-purposed tackle box.
Stahlsac Bonaire Mesh Backpack reviews and discounts, Stahlsac
To get to and from a hotel room, I have one of these from LL Bean:
http://www.llbean.com/llb/shop/63917?from=SR&feat=sr
I just put mine and my wifes bags in there and wheel it around. It is also watertight (not waterproof) so you can put it in the back seat of a car or trunk and not worry about getting everything wet.
Stahlsac Bonaire Mesh Backpack reviews and discounts, Stahlsac
To get to and from a hotel room, I have one of these from LL Bean:
http://www.llbean.com/llb/shop/63917?from=SR&feat=sr
I just put mine and my wifes bags in there and wheel it around. It is also watertight (not waterproof) so you can put it in the back seat of a car or trunk and not worry about getting everything wet.