Book fruit is cool and has plenty of visual potential. Mirror fruit is basically a gimmick that, while convenient, really works and creates some fun situations. I love how it can prove as useful as it is risky (if you're a clumsy idiot like Brulee).
The Meme Meme fruit is great :p Gave us one of the best moments in the arc in Pudding making Sanji forget about the kiss what with the panelling and the actual content of it, and the visual impact of actually cutting film off with scissors is really nice imagery. It's also terrifying in the amount of uses it could have, like actually mending memories and not just make people forget.
Pudding has to come back asap Oda.