IMO
The 4th generation ruled. The LS1 put the F-Body where it belonged, at the top of the pony cars. It held reign over the Mustang for all the LS1 years. It also had the best performance suspension ever and the power in the car is immense with plenty of room for growth. (EX: 0 to 60 in 5.0 seconds, 1/4 in 13.1 sec @ 106, the slalom at 66 mph, and pushing .84 to .88 g, with stopping 60 to 0 of 121) Any wonder I love this car!
The 4th generation was next to the vette, closer than it probably ever was. And because of this GM may have tried to diminish it in the eyes of it's customers to protect their Icon "Corvette".
If I had to choose a 2nd it would be the 1st generation for styling and the fact that their performance and power was probably better than the 2nd and 3rd generation gas saving (wuss era) cars.
That is IMO. B)