If you've ever liked a text adventure in your life, I recommend Phoenix Wright: Ace Attorney: Justice For All. However, I can't wholeheartedly say it's worth getting again if you already have it on the DS.
This game is an entertaining experience full of mystery, well thought out cases, and clever, often comical dialogue. With around fifteen to twenty hours of gameplay to be had, the ten dollar price tag also seems quite cheap.
Players who fell in love with Ace Attorney will no doubt view Justice for All as a must-have expansion to the first release. But those who were unconvinced that Phoenix Wright was the second coming of Atticus Finch are unlikely to be swayed by this new evidence.