I'll throw in one that hasn't been mentioned
The performance clause in the Ricky Williams trade was far too generous to New Orleans. As soon as I saw it, I screamed, "there goes another damn first round pick you moron!" Based on Wanny's philosophy and with a mediocrity at QB, it was inevitable Ricky's workload would be massive and the yardage would follow as a result.
It's near suicidal to give up two first rounders, for anyone, in back to back years. Those players should be making up the corp of our team right now. Instead, we're still relying on players from JJ's era in that mode and our overall personnel is below average.
Otherwise, I was shocked at drafting Fletcher, but even more shocked that he flopped so decisively. That kid made plays at Wisconsin, both in the secondary and in the kicking game.
Eddie Moore was a worse pick than Fletcher, IMO. He was undersized, always nicked in college, and never hinted as a blue chipper.
I think the major gaffe by this franchise in the past 10 years has been undervaluing athletic ability among offensive linemen. We draft stiffs, then wonder why they are overwhelmed by defensive linemen who have three times the agility and burst. Only when we stumbled upon pickups like Jamie Nails and Mark Dixon did we finally have a hint of athleticism on our front line and the positive results flowed briefly, until they were injured beyond repair.