How do I play a paladin without being a stick in the mud?

What are some tips for/examples of an epitome-of-good type paladin who does not disrupt the ‘sinful’ fun of the rest of the group?

As an example of the type of paladin I’m talking about, one of the first and only 3.5 books I bought was the Book of Exalted Deeds, and I’ve used it as guide for how I play good characters ever since.

As an example for those who’ve never read Exalted Deeds, I once played a Paladin who refused to kill any humanoid, and would actively defend defeated allies from other party members on the grounds that no one in the group was a judge, and thus could not render a death sentence. This did not go over well with the group, who quickly became tired of needing to haul around enemies to the nearest court, not to mention dealing with the occasional escape attempt on the baddies’ part. I felt I was playing the character as was appropriate, and the GM agreed with me on that fact. However, the group quickly deteriorated, as players began to grow bored of listening to my paladin preach at their characters to be better people.

I enjoy playing this type of character. However, not everyone enjoys playing with that type of character. So, how do I balance it so that I’m still playing my paladin characters the way I like them to be portrayed, without disrupting everyone else’s fun?