Orion was a fairly straightforward elf wizard. The character background was simple -- recently finished with his training, Orion was sent by his wizard master to investigate rumors of a lost temple of Oghma. Orion's player was a rather new gamer and fiance to the guy who played Boaz.
Boaz taught me a very valuable GM lesson -- do not make a significant portion of the campaign arc depend on a single character. He was a half-orc cleric of Oghma, the only cleric of Oghma anywhere, for that matter, since the god had not been worshiped in hundreds of years. I thought his background was pretty clever. Boaz had been turned to stone by some hideous monster or evil wizard and recently restored to bodily health. Confused at first, he dedicated himself to restoring his church. Thus, Boaz provided much of the motivation for the temple's exploration; he was a central character in the story, a protagonist in the sense of "he who moves the action forward." Despite voicing initial enthusiasm for this role, Boaz's player never really embraced it. Thus, I was faced with a priest of Oghma who never seemed very interested in exploring the temple of Oghma. That, coupled with in-game events, led to the game almost being totally derailed a few months in. It did lead to a significant departure from the game's original premise.
Kreed was another half-orc, though his player went with the traditional barbarian. A min-maxer, Kreed's player manipulated my character creation system a bit to come up with an insane array of ability scores. I take full responsibility here -- I should have said something up front, but I was also a little worried about the party's overall combat effectiveness. A really good fighter-type, I thought, was needed. Thus, the uber-effective melee combatant that was Kreed. I still kick myself for not having a little more backbone during this character's creation, as having a PC that was significantly better than everyone else in combat led to a host of problems in the future, as did the player's penchant for optimization and rules-lawyering. On the upside, many of the issues that Kreed brought to light were issues with the game itself, as they were changed when the 3.5 rules were introduced. One magic item in particular stands out, but I am sure Katja's diary will get us there in time.
I'll add at this point that I think all of these issues came to be well known by the gaming group in retrospection; they are things I think we all talked about at some point after the game ended (or had to address as the game was ongoing), so I don't feel like I am violating any confidence here. I hope any of the former players that happen to stumble on this blog feel the same way.