It is therefore the opinion, and only the opinion of this writer that no other vehicle can touch it for functionality, power, comfort or fueling options. I hereby challenge any and all comers to locate one vehicle model vehicle better able to fit more situations than a hopped up diesel Burb.
I've owned a Diesel Suburban since 1995 and a 6.2 Diesel Suburban for 4 years before that, so I would say that, yes a Diesel Sub is a great vehicle. But not the greatest vehicle ever made. IMO, that title goes to the British Mini. Now I'm talking the real Mini here, not the one they make today.
While it does lack the towing and passenger capacity of a Suburban, it was never designed for that. That is why they made Land Rovers. Over 5 million Minis were produced for over 40 years in numerous configurations. It was produced in many plants all over the globe and sold all over the world. Virtually every major car producer on the planet has - and still does - copied the Mini.
Functionality - The Mini was made in sedan, pickup, van, wagon, performance sedan, convertible sedans, upmarket sedan and utility configurations, just to name a few. In the various sedan configurations it could carry 4 adults and a surprising amount of cargo. The wagons had even more cargo capacity, while still carrying 4 adults. The vans and pickups were used in all kinds of commercial applications. Want performance? How about world beating performance? The Mini Cooper S beat all comers in International Rallyes. That is outright wins, not class wins. They were and still are very successful in road racing against more powerful cars. The upmarket Riley Elf's and Wolsley Hornets had wool carpets, leather interiors and even larger boots (trunks). The Mini Moke offered off road capabilities in a Jeep like body configuration. And we haven't even got into the custom coachbuilt or modified Minis, much less the Mini based kit cars!
Power - The Mini was offered in several engine sizes, from 850cc up to 1275cc. While that may not sound like a lot, in a 1500 pound car, it offered plenty of performance. The factory produced single and twin carburetors and on the later ones, EFI. If you wanted to go faster, there are dozens of companies dedicated to improving Mini performance. If you still want more power, there is a burgeoning industry selling Honda Vtec engine conversion kits. I have seen a kit to install a 400HP Vtec engine using a 4WD Honda parts that fits in a Mini. A 4WD sub 2000 pound car with 400 HP is more than enough for most!
Comfort - I suppose comfort is somewhat subjective, but the Mini set the standard for comfort in small cars. With its advanced 4 wheel independent suspension, its more comfortable than most think. As mentioned, there were Minis made with wool carpets, leather seats and wood dashes. Air conditioning was available in some markets. Automatic transmissions (4 speed automatics at that, long before GM had one) were available almost from its introduction. The Mini British Open had a power sunroof. The aftermarket supplied most any comfort accessory you may want, such as power windows, etc.
Fueling options. I'm going to say this is a wash and could really apply to most any vehicle. Stock Minis are pretty much limited to gasoline, but since you are allowing mods in the Sub, diesel Minis are not out of the question. I have seen 3 cylinder Daihatsu diesel engine swaps in a Mini. Plus, BMC made diesel tractors in the 60's. While I have never seen one, its possible you may be able to convert an A Series engine to diesel. So any fuel you could use in a Suburban, could be used in a Mini.
In the late 1990's there was a worldwide committee to evaluate over 700 cars to find the
"Car of the Century" When all the votes were in, the winner was the Ford Model T. Second place was the Mini. The Model T cannot be discounted as it allowed the common man to own a car. The Mini was really the first modern car. It showed the world that a well packaged car could offer economy, performance and handling, while selling for a very modest price. It offered reasonable comfort and a roomy interior in a very small package. I think the Cooper S was the first real performance sedan available to the masses. I just don't see how any vehicle (Suburbans included) can match the Mini in innovation or versatility.