The Cummins/Dodge is probably the best of the bunch if you're totally sold on the idea of a turbodiesel truck. I got to drive my sister's F-250 around this past week while visiting her family in Colorado. It's a pretty neat vehicle although there's some definite trade-offs. It's only available in the heavy duty 250 and up, not the cheaper F-150, it smokes and smells bad while warming up (although in September when ULSD is fully mandated in, at least the smell should be gone) and there's a fairly substantial amount of turbo lag at high elevation (7500-9000+ feet). For heavy towing, they're tough to beat, but even my sister's getting rid of hers in the spring because it's just too big for the kind of stuff they tow around.