I almost always raze AI cities that mess up my plans for overall city placement. I don't care if it has every wonder and is the holy city for every religion and has 20 settled great people... I just can't stand the moronic places the AI puts their cities and I feel like capturing one just because it has a bunch of goodies inside is like "giving in" to the AI's lack of foresight. No surrender, I say! If the world loses all its wonders because of the dumb AI, then they asked for it!
Yes I know it's just a game... I get way too involved and personal with it