Trans Ams, Firebirds were some of the creams of the Automtive crop in the US as far as styling goes. While some may not have cared for the endura bumper, compared to the fully exposed and grinning grills of some of the other cars, it was, in my opinion, very appealing.
Years I like are 67-69, 70-73, 77-78, 82-90, 91-92, 98-02.
74-76, 79-81, 93-97 are the low points in styling.