The Avengers version for me. I like how it includes the silver piece at the end of the handle--where the leather strap is attached--from the Thor: The Dark World
style and the v-pattern hilt from the Thor
one. Seems like the section where the strap is attached is also a mix between the two versions from the Thor movies, but that might also simply be the camera angles...
I just like how it uses elements from the other two, but that's just my opinion.