What's the main reason you Jailbreak your iPhone, iPod touch or iPad? Is it for themes, so you can change up the whole look and feel of your device? Is it to unlock so you can run it on T-Mobile or travel internationally? Is it convenience, so SBSettings and BiteSMS can keep you going faster? Is t coolness, so you can show your friends the icons rolling around your screen or how you can turn your device off like an old TV? Is it Tethering, because you feel like you've already paid your carrier once for that data? Is it functionality, because you want your screen projected or recorded?
Maybe it's all or most of the above, but if you had to pick just one Jailbreak feature that's most important to you, what would it be?