When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Stay away from the 4.2 liter. After that it is most important that you buy a truck from someone you trust. Meaning that they have done the regular maintenance and can proof it. I would never go to a used car lot and just get someones old truck. Try to find one locally and check out the people that own it.
In the past I have owned a '96 F-150, '99 F-250SD, '00 F-150, and now an '03 F-150.
Of the four, the one that has given me the most problems is the '03 F-150, and I have only had it for 2 months so far. Next in line would be the '99 F-250SD, then probably the '00 F-150 and the '96 F-150 would be pretty much a tie for best one.
In the two and a half years that I owned the '00 it did not go in for any mechanical problems, but it was in the body shop for a door crack and rusting door bottoms. I owned the '96 for two years, and it went in only once for a noise that ended up being a loose shock.