He was still looking for his niche back in the 90s - he was still trying to figure out how to a) be a commentator and b) be Bill Walton. Once he learned how to do B, he took off. He was also on hand for the ESPN broadcast of the Malice in the Palace back in 2006.

Once he switched over to college basketball (the Pac-12 in particular), that's when he really started to become a national treasure. As Go already pointed out, he made unwatchable Pac-12 games must-see TV.