3G unrestrictor - facetime over 3G (the first real world use ive seen for 3G unrestrictor)
Quick Reply - once you have quick reply, you are never going back to normal texting on the iPhone again
Categories - 12 apps per folder is a bust
MyWi - grandfathered unlimited plan and going on a lot of trips with no internet this summer
Winterboard - Regular app icons are so boring, plus I love taking like 5 or so themes that match each other and spending a few hours making my iPhone look completely different than anyone elses
SBsettings - being able to adjust the brightness wherever I am actually is such a nice feature
Tap to Unlock - Saving me .2 seconds every time I unlock my phone, thats like a total of 7 years of my life or something right?
those are my top reasons, but whenever I get bored I go into Cydia and just stroll through the apps until I find one that looks interesting, then all of a sudden I get to use my phone as a completely new device
Anyone who isnt completely stupid when it comes to technology should jailbreak their device, you are paying so much for it and yet you seem to never use it for all that its good for, like clipping the wings of a bird. Oh so sad, *tear tear*