Normal Wear stuff: Brakes, tires, wipers, battery, exhaust, headlights, etc.
Rear defroster never worked and I repaired it many times.
EGR value replaced
Oxygen sensor replaced
Oil filter O ring leaked and was replaced.
Fuel injector unit replaced at 82000 miles
Gas tank rusted through and needed replacement
Both front fenders have completed rusted through due to the plastic molding that GMC put on it which collected water and rotted the metal.
Front brake line rusted through
Coolant & Oil Sensors replaced
Aluminum wheel rims are always leaking air and are cleaned and repaired twice a year.
Governor case on transmission rusted through.
Transfer case relay failed and needed replacing or else 4 wheel driver would not work.
There was a time that I lost complete faith in this vehicle at about 80,000 miles when everything started to go wrong at once. But once I repaired everything, it was good for a long time.
Now my biggest problem is rust and I believe the reason was because I keep it in the garage for a year or two mostly in the winter. The condensation and moisture in the garage just soaked the metal and caused it to deteriorate. I believe if I had not garage kept it, it would have a lot less rust then it does now.
This vehicle has been my workhorse and my friend. Even with 105,000 miles on it, I would have not qualms about driving cross country with it.