I would go Easley, Adalius, Jackson, Maroney, Chad Johnson, Duane Starks, then probably Ras-I. Easley is the worst to me because he couldn't stay on the field on top of being somewhat of a head case apparently. One of the oddest picks all around in the BB era. Odd scheme fit, odd personality, bad knees, and bad attitude and all of this seemed to be out there before he was drafted.
Adalius has to be up there as he was really the only major splash FA signing Bill ever made (that was a big name at the time of the signing). I remember hearing about how he could play any LB spot as well as DE and even safety. He played well in '07 especially when Rosie went down but things seemed to go downhill fast with injuries and the whole snowstorm ordeal.
Jackson I thought was going to be what Bethel Johnson was supposed to be and couldn't even manage that. As for Chad Johnson I thought there was something left in the tank and physically maybe there was but he was too simple to understand how to play receiver in our system but I will always respect him for keeping quiet and doing what Bill asked as far as the media aspect.
Maroney was a bust but I don't feel like he was as bad as most people do. He just wasn't a full workhorse guy in a time where having a workhorse was the norm. He needed to be paired with Marion Barber or Corey Dillion and be more of a 10-15 carry guy as opposed to a 20ish carry guy. When he took over as the lead guy he couldn't take the pounding and it seemed to affect him mentally as well as physically.
Duane Starks was one of the worst Patriots I remember watching in the BB era. He couldn't cover anyone and drove me crazy. Ras-I is similar to Easley in that he was a major injury risk before he was drafted and couldn't get on the field.
Some honorable mentions: Jermaine Cunningham (esp since Urban apparently told Bill to take Carlos Dunlap instead), Terrence Wheatley, and Ron Brace.