16. 2000 GMC Sierra
The 2000 GMC Sierra was the second year for the new design of the truck. For the most part, the truck was a well-appointed upgrade over the previous generation. Common issues for these trucks were relegated to electrical malfunctions and the like. These trucks also had problems with the lifters failing. While the generation had a lot of advantages over it the main drawbacks of the 2000 model year make this a truck that you should avoid. Although this generation of the Sierra / Silverado was one of the most reliable for the decade. The drawbacks made this truck more or less worth avoiding.
The mechanical aspects of the truck make it a bit expensive to maintain and drive. Which is why a good deal of owners tend to turn these trucks away. Especially on the used market, where repairing a high mileage pickup truck can end up being a pretty expensive thing.