9. 2004-2006 Pontiac GTO (LS2)
The later 2004-2006 Pontiac GTO models received a significant boost with the 6.0-liter LS2 V8, raising output to 400 horsepower and delivering sharper performance over the earlier LS1 versions. These “sleeper” GTOs remain under the radar, but their increased desirability is evident, thanks to robust aftermarket support and limited production numbers. Collectors and enthusiasts alike appreciate the subtle styling mixed with raw power, making these LS2-equipped GTOs a compelling choice for future appreciation. Source