When most people think of their "dream truck" they think about big power or big accessories. I think what I'd rather have is a truck with things like:
-No rivets anywhere. Only welds or threaded fasteners
-No self-tapping screws anywhere
-No plastic "weatherpak" electrical connectors - only aluminum environmentally-sealed circular connectors. I hate plastic electrical connectors - they always seem to break when you remove them.
-No "push-on" "quick disconnect" fluid couplings. Only AN (jic) fittings.
-No grade-5 (and below) threaded fasteners. Only stainless steel fasteners or grade 8.
-More use of corrosion-resistant materials like aluminum (which oxidizes, of course, but not catastrophically like steel). I'd love to see frame rails made out of solid cast aluminum or, even better: titanium ($$$).
-Accessibility. What I mean is, body panels that are designed to be removed quickly and easily for access to components for maintenance. And body support structures that are positioned to allow for things like easy engine and transmission removal. I'd love to be able to pop a couple stainless steel bolts out of my front body work to remove it for access to the sides of the engine (sort of like a big rig with the hood tilted forward). How about the ability to completely remove the body from the vehicle with just 1 or 2 electrical connectors and several bolts?
-No more stamped steel structural components. Use either cast aluminum or cast iron (personally, I'd rather have a nice set of cast iron control arms than stamped steel or cast aluminum - I don't care how much they weigh).
-No more stamped steel body panels. I'd much prefer a strong fiberglass body that never rusts and can be repaired cheaply. I still think Saturn had a good idea. But don't bond the panels to the substructure - bolt them. And make the substructure from aluminum.
-Include a backup manual mechanism for electrical systems like power windows and electronic transfer cases.
-Stop using battery cable - use welding cable instead. It's more flexible and easier to work with.
-Eliminate the starter motor and use a switched-reluctance starter/generator (this is already starting to happen) on the accessory drive.
-Integrate engine accessories to minimize the size and complexity of the belt and mounting hardware on the front of the engine. It would be awesome to see a single belt running an accessory drive transmission assembly containing alternator, water pump, and P/S pump. The transmission would be bolted to the side of the engine block (or perhaps the transmission) and each of the accessories would be removeable for service. Perhaps include a low-horsepower PTO port on it.
-No hose clamps. Only compression fittings, AN fittings, or bayonet-style couplers.
-A fuel tank with a drain on it.
-No plastic radiator drain valves. Use brass ball valves.
-No gas tank straps mounted directly to the frame. Instead, strap the tank to an aluminum "tray" that can be unbolted from its support structure and lowered.
-No more rubber. Only urethane.
-No more of those plastic interior trim retaining pieces. You know, those things that look like a fir tree and never fit back together quite right after they're removed once. I suppose if I designed an interior there'd be little bolt heads showing everywhere. :-laf
-No more snap-together anything. It either bolts together or it's not on the vehicle.
-For trucks, no more carpet on the floor or the headliner. Or at least make "carpet and headliner delete" an option independent of trim package.
-No adhesive-backed tape anywhere. Especially not electrical tape.
A truck built like that would be my "dream truck". I suppose it would also weigh 20k pounds and cost as much as a Porsche 911 Turbo. But it would be bomb-proof and easily serviced.
Some day I'll take a vehicle, tear it down to the frame, and rebuild it the way I really want it. Probably the day after I win the lottery [mental note - start playing the lottery].
And Traildog - a Defender rebuilt from the ground-up with a 4bt is my personal dream vehicle.
-Ryan
Attention: TDR Forum Junkies 
