For me I think it was McDermott's first season. I was unsure about him when they hired him. Seemed conservative and like a younger jauron. After he started Peterman, and then rallied the team to stay together and get to the playoffs (with a little help of course) I knew he was different from previous coaches. Admittedly, drafting Allen had me concerned, but we're all past that and we've all seen what happened since.
On a side note, during those drought years, I think I actually got to a point where I thought we'd never make the playoffs again. It's crazy what us bills fans endured for almost 2 decades