I've actually never had anyone try to play a Paladin in any of my games, or any of the games I've been in... *I'm* the only person who's tried it, and my DM thought I did a great job. My character risked her armor and other metalic equipment when she attacked the villain's rust monster pet to keep it from ruining the rest of the group's stuff (they were running from it). Her sword was made of crystal, so it was immune, but she did lose her armor in the deal. The DM said that was the most Paladin thing he'd ever seen a player do... it was perfect. I just said "Well, someone's gotta do something, and I attacked without a second thought to my material possessions.
The character ended up sacrificing herself to defeat a possessed knife (I think this was a published 2e FR adventure, but I can't remember). To stop the knife's murder spree it was necessary to stab it into the heart of someone pure, and well... she fit the bill, so she sacrificed herself for the good of everyone. She came back later in the campaign as some kind of valkyrie kinda being in the service of Tyr. I thought it was fitting.
I've played Star Wars for awhile though, and anyone playing a Jedi in them was and is informed that I am very strict with dark side points. Under the old d6 rules, I gave out dark side points on more than one occasion for boosting your lightsaber damage when attacking normal troops, since it was overkill and unnecessary.
I even gave a dsp for a Jedi player using Affect Mind on someone to fudge with their memory just because they didn't want to go through the motions of asking the proper people for authorization about getting ahold of some equipment. The player made the assumption that they wouldn't be able to get what they wanted through normal channels, and used affect mind to get what they wanted... sounded like the epitomé of "quick and easier path", so I dinged him with the dsp. The player argued with me over email for a solid week and then quit the game.
Now, the player had been very troublesome in general, and this wasn't the first arguement I'd had with him, sometimes over hyper-trivial things (to my perception), so I didn't see it as a huge loss for him to leave, just so you know I wasn't being a complete ass. He still had a very skewed idea of what being that good was all about..