I've got an '05 Ram 2500 laramie that's been in the family for ... 6 years? 250,000 showing on the odometer (mind you that's in Kilometers) on the 5.9 cummins. Absolutely love the beast. Chipped, cold air intake, free flow exhaust. It's funny when I destroy the young guys off the line ... while towing a horse trailer or boat.
Preloading the drive line and putting her into 4x4 is essential to getting a good launch. LOL!
Only real issues I've had is recently replaced the water pump, power steering box, and various front end parts and u-joints.
If I drive it right i can get around 30 mpg (and thats with an approximate 500lb custom bed cover w/headache rack and slip tank plus over sized tires).
If I could still get it I'd buy another one new off the lot in a second, but I can't. I'm not a big fan of the new style diesels and the additives.
My parents had a 90's era 1500 for years and years ... before someone decided to steal it with over 450,000 on the odometer!