Well, there's plenty of amazing fan art. Just looking at some of the unique customs done with NECA and Hot Toys are proof of that.
JUDAS BREED
Some really cool figures done by this guy. I love "The Forgotten."
Figurerealm also has some really cool looking custom/unique Predator builds.
However, the fan art department has also generated some awful shit. Art, is art. There's good art, and bad art, in all circles. Often with a production like this, there's a lot of concept art created by a number of different artists. Just look at the concept art section for the original AVP film and you can see some pretty extreme redesigns for the Alien and Predator.