Memory.
I'd love one that can remember EVERY detail. Like what I was like when I was 2, or how to recruit Katida in Infinite Space (too late now), or each and every item's name in Final Fantasy III-DS. Just random examples...
(Funny there's no "Final Fantasy 3DS" - just for pun, of course. But I'd like to play as Warriors of Darkness AND Light...)
Yeah, it's kinda hard to get information on wikis sometimes. As such, you'll probably have to contribute to them by adding information. Besides, the Dragon Quest Wiki's gotten much better since I contributed it.
Though I'm sure if you
had a computer, editing Wikis (i.e Lunar Shadow Project Wiki) is something I can see you doing.