I just went last week on a diesel truck test drive expedition with a buddy. We drove similar trucks from Dodge, Chevy, and Ford. Each was a diesel automatic 4x4 crew cab. The Dodge and Ford were both single rear wheel models, while the chevy was a duel wheel 3500 since they didn't have any other diesels in stock. For your purposes, I'd recommend the Chevy. I've also driven other trucks from these 3 companies at work, since we make drivetrain components for all 3, and a bunch of others. Here's the breakdown as I observed:
Engine/Transmission: The Ford wins hands down. The ability to rev as high as it does, combined with ass-kicking torque is amazing. The Chevy is an incredibly close second (nearly identical, but the Ford just felt goooooood), while the Dodge was a distant third. I know I'll get a lot of s*** from you cummins-humpers, but for his purposes and my purposes, who needs a semi engine in their truck? It might have the highest torque, but it's all in an incredibly narrow range. If you have a 20 speed transmission, you can pull a house off it's foundation and run it up to 80 mph down the highway. Whoopty doo. The dodge comes with an antique 4 speed automatic. If you wanted a 6 speed stick, then the cummins would be a viable solution, but most people do not want a stick shift massive truck. The Chevy and Ford both have 5 speed automatics, and feel nearly identical. My company makes the torque converter for the Allison automatic in the Chevy, and I can tell you it's easily the best transmission of the group if not the best of all time. We also make parts for the Dodges and Fords, so I'm not really biased here. Anyway, Ford wins while Chevy is very close behind. If Dodge would put a 7 speed automatic behind the cummins, I would have no problems recommending it. Even with a 6 speed, which I've also driven, the narrow torque band really kills the drivability of the truck.
Ride/Handling: The Chevy wins this category with flying colors. I've driven several 2500s and a 3500, and honestly the 3500
with the heavier springs still rides better than the Dodge or the Ford. The clear reason for this is the independant front suspension on the Chevy. The 4x4 Dodges and Fords that are 2500 level or higher all have solid front axles. This may be good for mudding or learning about the history of axles, but Chevy is the only one of the three to have moved into the 21st century here. It rides and handles much better than the other two, hands down. The new models of Dodge and Ford are nearly identical with ride, since this year Ford finally threw away their front leaf springs and went with coils. Any Ford older than 2005 rides a bit rough and a bit springy. The Dodges have had coils for a few years now. It seemed that the Ford turned sharper than the Dodge, but the Ford was a short bed model while the Dodge was a longbox. Maybe you can look up turning radius and compare the two this way if it's important to you.
Interior/amenities: The Ford and Dodge have nice interiors, but the Chevy's is a little boxy and utilitarian. I like that myself, but the guy who test drove with me liked the Ford's interior the best. It was a Lariat package however, so take that at what it's worth. The Dodge has a hard plastic dashboard, the Ford has a soft one, and the Chevy is somewhat in between. The Ford is the cushiest of all 3, the Dodge and Chevy are both a little more "truckish."
Overall: I like the Chevy, the guy I went with liked the Ford. In reality, they're pretty close. The Chevy doesn't have quite the engine, but the suspension and transmission more than make up for it in my mind. The s*** transmission in the Dodge really killed it for me, but I know dedicated Dodge boys will buy anything with a ram's head on it. I guess it just depends on what you want. If you don't have a massive trailer, then don't get the Dodge. Even if you do, get the 6 speed stick so you can actually use the engine to it's potential. I've owned a dodge truck and a chevy truck, and I drive a Mazda(Ford, sorta). I've driven Fords, Chevys, and Dodges to hell and back for work at this job and at my last 2, so I'm not really whoring myself out to my own biases. I like them all, but I love some. I can't say much about Toyota or Nissan since I haven't driven either. They don't make a diesel anyway, as far as I know. I can vouch for Toyota's quality policies however. The products we make for them are put through hell before they will accept them, wheras other companies take whatever we give them and just run with it. I assume Nissan is the same. However, if you'd be willing to forgoe the 4x4 and diesel, I'd wholeheartedy recommend the Dodge SRT-10 Ram. It's by far the best truck I've ever driven, for obvious reasons. It's really just a hell of a deal for only about 6 or 8 thousand more than a diesel. If you ever drive one, you'll never want anything else in a truck. You can even get it in a quad-cab.
