Jailbreak vs Non-Jaibreak iDevice

Has we all know that since the release of Apple iPhones a few years back, jailbreak was somewhat illegal well thats if you get caught by apple, then you will void your warranty with apple, but everyone who jailbreak there phone still take this risk and say screw it and do it anyways. I am one of those people because I Think if I pay so much for my iPhone I should be able to do whatever I want with it. Has a few months ago Jailbreak is now fully legal and almost everyone is doing it. So tell me what you think is the Advantages of Jailbreaking your iDevice or keeping it the way it is is better?