Has to be ray wilkins for me, the guy is a total moron. Every interview at chelsea was unbelievably biased. Then since being sacked, he's just carried on his chelsea bias (or english bias in champs league - see spurs vs ac milan commentary) everytime he speaks.
Obviously every english commentator will favour english teams in europe (even though their job requires them to be neutral), but he just says **** like "well (e.g.) Ibra was clearly offside there, no doubt about it", even though it was close. Then the replay comes up seconds later proving him wrong and he doesn't even correct himself. First example that came to my mind, but I could list them all day.