Is this about what powers you would like to have in real life or which you found the most enjoyable when watching/reading? I'll assume it's the latter.
Personally I found HxH's usage of Nen to be the best. It might seem similar to chakra and jutsu, but it's utilized differently. Some things I like about Nen are...
+ A Nen ability is almost always unique to the person, it's not something passed down to other people like the Fireball jutsu
+ The aura of Nen gives characters a legit reason to not suffer injuries after being hit by an attack, while in Naruto it's usually more limited
+ Tricks involving Nen have some neat properties, such as making a technique stronger by placing restrictions on it (such as Kurapika) or after death
I love how creative jutsu can be too, I just think there's some redundancy at times. Every capable ninja being able to make clones, for example, seems off putting to me. Genjutsu also seems a bit broken... I liked how Kakashi used it against Zabuza, but I'm not a fan of it being an instant paralyze technique or whatever
