There are loads of them, aren't there. Adrian's question about chapters got me thinking about them all. Don't make your chapters too long, don't use a heavy accent for a character for too long, don't use too many adjectives, don't jump POV too often, murder your darlings, blah, blah, blah...
Are there ever excuses for breaking the rules and would you break any for your story?
Interesting question, Victoria.
Much would depend on the plot, storyline and genre of the book.
A couple of suggestions below, but they may not be original ideas.
You could have characters acting out of character. You could have characters with split personalities, or other mental disorders. That would allow opportunities to experiment.
You could have a third person narrator, who changes to the first person, and then becomes a rounded character in the story.
I think some rules are made to be broken and that's why some people stand out from the crowd in a positive way - because they dared to do it and succeeded and the rule break worked for them. The other thing is whether the rules are set in stone and who set them - who made it a rule? Sometimes rules and boundaries need to be pushed to set new standards and ways of thinking. That's just my opinion of course :-)
I would only really break a rule if I didn't know I was, or if I really had too for one reason or another.