@takashichea: True, but they aren't impossible to find, I think wiki editors just focus on anime more. Artwork, volume coves, chapter covers, and full-page or two-page spreads are often good for portraits.
It would be nice to know what those portraits you posted are from, by the way. I always caption mine.
@Bigheart711: I appreciate the effort but most of those portraits aren't really following the guidelines. The idea is to have the face fill the top square of the image like the ones in my previous posts. The girl with the tiara/crown is decent but the others are pretty far off. I realize you may be limited by your source images, of course. For the little guys (the plushy-looking creatures) you can just make square portraits that show the entire body, since they're so small.