I've got a serious soft spot for the Wheatley clip boxes...they make a great box because they are light, incredibly and durable, hold a lot of flies and most importantly, they protect them.

The clips allow me to lay my flies on their side which protects the wings on my bucktails and with the deep box, I can lay a Spey or Spade on it's side, pull it out when its ready to be fished and the hackles are as full as they were the day I tied it. I am just sure to open them up and let them dry (like any flybox) after a day of fishing to reduce rust and color bleeds.

If you really want to get fancy, take a look at the C&F Flyboxes...they come in all differnt shapes and styles and come with removable swing leafs and removable inserts.

The one I would recommend would be the Large Fly Box...it is very deep, totally waterproof and very durable, plus I believe it floats. The only downside is they are a tad heavy and bulky.