Samuel
Law
Seymour
Spires
Vinatieri
Those spring immediately to mind
Samuel - a great ballhawk and zone pass defender, but also among the worst CBs in the league in run support and tackling. He's another guy who is a good player, but one with flaws and certainly not worth all the money he got from the Eagles. Just ask an Eagle fan. I don't regret not matching that absurd contract offer he got.
Law - had 10 picks with the Jets but had Jet fans moaning about his coverage the rest of the time. The Jets were so impressed with his 10 pick season, they let him go after it.
Seymour - Played decently in Oakland...when he was on the field, but never came close to playing to the level of the absurd contract he received. His play has regressed to the point where he'll end up being a June FA pick up for someone looking for a below $2MM run stuffer.
Spires - Now that one is a stretch - He did have a nice career after he left the Pats. He even had an 8 sack season one year for the Bucs, but didn't average 5 sacks of the rest of his career after the Pats. Just because he played in the league after the Pats didn't mean e excelled
Adam - He comes the closest, but his replacement has done just as well.
Like in most of the decisions BB has made since he's been here, he's usually right. Not every time, but MOST of the time. I expect Welker to be Welker in Denver 80-100 catch, depending on how often they throw it to him. Just because he does well, doesn't mean BB made a mistake. If the Pats offense remains in the top 5, then he didn't