8. Jermaine Pennant
At
£6.7 million, Pennant is far from the most expensive player on this list, but Pennant was a special kind of bad. After being deemed not good enough for Arsenal, he joined Birmingham City where he flourished in his sole season there. Benitez, who always had a problem identifying talent in winger, thought Pennant good enough for the reigning FA Cup champions. He was wrong. If Jermaine Pennant was even a tenth as good as he thought he was, Liverpool would have been blessed with a great player. Instead, they got a lazy and self-destructive force who only had two notable moments in his entire tenure - the Champions League final which Liverpool lost anyway and his wonder goal in a 2-0 victory over Chelsea. Pennant never came close to being what he could have been and is currently lingering on loan at Wolves in the Championship.