John Crichton said:
As a player... hoo boy. I am a big-time rules lawyer. It annoys me when the rules are done wrong and I ALWAYS say something, no matter how big or small if I pick up on it. I especially hate it when a another PC "gets away" with something. Just bugs me to no end. My salvation: My current DM is really good. He knows his stuff and while I may pull out the rules lawyer stick, his is just as big, if not bigger. His rules-fu is strong and he indulges me from time to time by checking the books if he is not sure.
You'd be welcome in my game any time. My last campaign, one player was a friend of a friend whom I had previously met only once. We were both long time gamers with lots of DMing experience. His third edition experience was greater than mine.
I had rustled up players by saying that I wanted to run my first 3E campaign as close to the core rules as I could, having read them and been surprised by how much I thought I liked them.
He frequently called me, in a friendly, polite way, if he was aware of me making an error that he thought was important. He would sometimes do this when the correct ruling went against another player. If his call favoured the party or his PC in particular, he had a tendency to phrase the challenge as a query.
But he was usually right and able to reference quickly. When he was wrong, because of course he sometimes was, he happily acknoweldged it. If he caught me out on trivia, he'd let me know it, grinning geekishly at the end of the session.
I still managed to show him a few tricks.
His roleplaying was spot on and entertained the whole group. He was one of the best players I've ever met, not that I'd ever tell him.
Shame we've both relocated beyond the bounds of viable, regular game commuting recently.