First get some cars to compare :
-Porsche Cayenne
-Porsche Cayenne Turbo
-Hummer H1
-Hummer H2
-Hummer H3
-Range Rover Vogue
-Range Rover Sport
-Lexus Lx 470
-Lexus Gx 470
-Lexus Rx 330
-Acura RDX
-Acura MDX
-BMW X5 4.4
-BMW X5 4.8
-BMW X3 3.0
-Mercedes ML350
-Mercedes ML500
-Mercedes ML 55 AMG
-Mercedes GL500
-Toyota Land Cruiser
-Toyota Hilux Surf (4runner)
-Toyota Rav4
-Toyota Land Cruiser Prado V6
-Honda CR-V
-Honda Element
-Honda Pilot
-Ssangyong Rexton
Although, people have rated Land Cruiser to be the worlds best SUV, then Range Rover and then Hummer. Hummer was considered to be rated lower ONLY because of its terrible fuel mileage i.e, 2 miles per gallon, or 1km/litre !
However the 2007 Mercedes ML series has gotten some serious awards, so I guess thats probably a great one!