I test drove all the full-size pickups prior to making my purchase and the Titan just felt more solidly built. It rides extremely well has plenty of power and fit and finish exceeded the other vehicles except the Tundra. The Tundra was fine, I just don't like the external styling however I am sure it is a fine Truck. The Titan also has a lot of well thought out features that just makes sense for a truck owner. The American made trucks (I bought used) just seemed like they aged faster than the Titan. My Titan still feels new while the others didn't. I average between 14-15 MPG which isn't great but is a good tradeoff for the power and responsiveness. I expect this truck to last me 15 years easy.
Other than fuel mileage, the room in the cab and the pickup of the engine and the style of the truck.
Bought the truck new in 2004. 7,000 lbs sports car. Brakes were an issue at first but Nissan corrected the problem and I got 120k miles on the new rotors and pads. NO motor or transmission problems. Excellent body hardware. 18 inch tires last 75k. Just oil changes, 2 batteries, and tires. The oil pressure sending unit went out but I fixed it myself. No other large truck drives like this. The truck is fast, agile and solid. It still runs like the day I bought it. I have 145k miles on it. As far as mileage goes, none of the large trucks get great mileage. The titan only gets about 12-13 mpg around town but freeway is much better at almost 20mpg. Considering the cost of auto repairs, the gas mileage is not an issue because this truck is built with quality parts that that will outlast most other trucks. My dodge ram 1500 went through 2 water pumps, 4 sets of brakes, a tranny and cracked the heads at 120k miles.