I mentioned this somewhere else recently, but Mikael Silvestre had an amazing half a season in 03/04. For the first half of that season he was brilliant at centreback, I remember the general consensus on this forum was that he'd been our best player and second only to Henry in the league. There was one specific defensive action that I always remember that literally got me on my feet as I watched it on tv, with the opposition (which I always feel was Newcastle but I could be wrong there) launching a counter attack and having a 3v1 against him with our entire half to run into. He took out the first player near the halfway line as he passed it, sprinted over and slid in to dispossess and knock over the second player, the ball rolled to the third player near the sideline and Silvestre was instantly back on his feet and ran out to put in another sliding tackle that put the ball out of play and the attacker on the ground. 3v1 and he didn't just stop the attack, he stopped each and every one of them individually. Loved it, and I've always wished I could watch that back or just remember for sure which match it was.
Of course, that half a season turned out to be a massive purple patch, with Silvestre falling apart as soon as Rio got that suspension in January for missing the drug test. He never got remotely close to that level again unfortunately.