What is the most durable tablet?

If you're talking seriously durable, it doesn't get more so than this. Made of die-cast magnesium casing and is dust and water resistant. The screen is viewable from outside and weighs in at less than 4 pounds. There are some that are more durable than this and have been drop tested but some are military tested and approved making them weight similar to that of a laptop (6-8 pounds). I'm not sure it's exactly what you might want to consider, it's certainly not thin like an iPad, but definitely durable.

Reply · Send thanks · posted 95 days ago

Panasonic Toughbook H1

Panasonic Toughbook H1 Tablet PC CF-H1BDBAZ6M 202 read more...

If you're really serious about this you could even consider Panasonic's Toughbook tablet.... but it's kind of a tank! Probably unnecessary, but not a bad looking tablet. It has an Atom 1.86GHz Z450 processor, a 64gb solid state drive and a 10.4-inch touchscreen, plus a battery life of about 6 hours. Not the best, but certainly durable. Although, I do have to say that Gorilla Glass on the Eee Pad loks pretty good, too.

Reply · Send thanks · posted 95 days ago

ASUS Transformer Prime TF201-B1-GR

10.1" WXGA (1280x800) (LED Capacitive)/NVIDIA Tegra 3/1GB DDR2 RAM/32GB Flash Memory/Android 3.2 (Honeycomb)/802.11BGN/1.2MP Front Camera/8.0MP Rear Camera/Bluetooth 2.1/Up to 12 hours battery/G-Sensor/E-Compass/GPS/Light Sensor/Gyroscope/1YR Nort... read more...

I would think the screen is the most important aspect of the "durability rating" here. The Eee Pad Prime uses Corning Gorilla Glass for its screen, so I think this would be the best choice for you. That stuff is tough tough tough.
Also, you mentioned that you travel a lot, well you will also be pleased to know that Eee Pad has some of the best battery life in the biz, at 8-9 hours by itself and up to 17 hours with the keyboard attached.