Best Truck: 1992 Chevy C1500 (W/T 1500) 2wd, 4.3 V-6, 4 speed AT. Reg Cab 8ft bed with a 3.42 rear axle ratio. Bought it new and still have it. Rides nice, fuel miser (23.5 hwy mpg), tows decent (15.5 mpg). Just overall dependable and been cheap to own all these years and its been worked hard.
Worst Truck: 2001 Chevy Silverado Ext Cab 6.5 bed 2WD 4.3 V-6, 4 speed AT, and a 3.73 rear axle ratio. Only vehicle I have ever ordered. Bought it new but only kept it a couple years. Supposedly had 40 more hp than the 1992 but I never found em. Gas mileage much worse than the 1992. It was totally reliable and dependable for the 70K miles that I put on it, but it would shift into OD in town and shudder due to lack of power around 35 mph. Pain in rear to lock out O/D all the time. Towing same loads as 1992 the truck struggled. Tow in Drive and rpms too high and past the sweet spot of the V6 (would not have been the case with the V8 as those like to rev). Not enough oomp in OD with the V6. Truck Would have been better with the 3.42 rear axle ratio I think with the V6. Towing in drive with the 3.42 would have put the rpm in a better spot of the V6 curve. I overthought this option when I ordered it and picked the wrong ratio for the V6.
Most fun truck: 2003 GMC Sierra 1500 4WD, Ext Cab longbed, 5.3, 4 speed AT, 4.10 rear end. Traded the 2001 in this one as a used unit. This thing is a beast for 1500 series. Runs well, tows well. Not a fuel miser, but not a gas hog either. Still own it and plan to for 10 more years Truck eats brakes but otherwise has been reasonably reliable but has had its fair share of simple little annoying fixes too. Luckily most have been cheap.
Have a few honorable mentions but those were not asked for...