House Rules

It may be unpopular of me, but I really don't like house rules. I know this game is a little sticky, and some things are up for interpretation, so I understand that, but I really don't like house rules that (to me) just completely mess with the game.

That being said, for those of you who use house rules, what are the rules you use? Why do you have them? And are there any in particular that you have used or heard of someone else using that you particularly love or hate?

This is a post I have been thinking about for a while and I just wanted to know what you all think! I am willing to have my mind changed if I am completely in the wrong!