Ok, with my Honorable Mention gone out to the diesels, we'll get on with the list. I was lazy and picked only 5, feel free to chime in where you think I'm wrong after the final list has been posted.
5. 454SS. Chevy went old-school with the 454SS. They took a regular cab, short bed truck and jammed the biggest engine they made into it. Unfortunately, at the time the 454 was only putting out 230hp. However, with 385-lb-ft. of torque, the SS was no slouch. With the foundation already there, a 454SS truck would make a solid candidate for some modern engine upgrades, like our buddy Alan Beers did with his. Add a new set of heads, an intake, a cam and you're well on your way.