John Rocker - I remember being at a playoff game at the dome in 1998 or 99 (I think) late in a tie game when we had the bases loaded and Rocker came in and got all three outs and the Braves ended up winning.
jay powell easily...no one gave up more clutch hits against the astros than him. i'd also say brian giles, edmonds, and pretty much anyone on the pirates or braves. and tony esusabio was the slowest professional athlete EVER.....