This is still my greatest moment at a poker table, after several years of play. I was playing Texas Hold 'Em (of course), and held pocket kings. The pre-flop was aggressively raised which was fine. The flop came in AJK, more raising and I was starting to get scared of pocket aces and straights. Then came the glorious turn, another King, at which point the fishy next to me went all in. I thought about it long and hard, then 'grudgingly' went all in. The look on his face was priceless, his full house nicely worthless. I also managed not to throw away my chip lead and came away the eventual winner!
Those were the days!