Updated rank:
1) Stephanie Nadolny (DB Goku > GT Goku) - She's everything I was looking for in the voice, it's the most distinct of them too. She also did a great Goku Jr.
https://www.youtube.com/watch?v=1CgwpecWlWc
2) Barbara Goodson - Is the closest to Masako Nozawa, and holds up on its own. Some of her lines are a bit uneven-sounding ("Uh-uh, this ball belongs to by grandpa, he gave it to me", but it doesn't really detract from the character.)
3) Saffron Henderson - A bit more collected than it should be, but not bad.
4) Zoe Slusar - Not the best, but gets down all of the major aspects of his personality.
5) Ceyli Juliann Delgadillo - The acting/characterization are poor and lacking in energy, but the voice itself is one of the better ones.
6) AB Groupe UVA - Basically Barbara Goodson with terrible acting and line delivery. The voice is at least cute-sounding, though.
7) Kirby Morrow - The voice isn't age-appropriate or fitting, but at least it's not too grating.

Colleen Clinkenbeard (Xenoverse GT Goku > DB Goku) - The acting isn't terrible, but it grates, and the voice doesn't really fit him either. As others have said, she does little to distinguish it from certain other roles.
9) Brianne Siddall - The energy is certainly there, but the character she's voicing isn't Goku in any way, more like some "cool", "badass" kid hero.
https://www.youtube.com/watch?v=Vf9jzu-JFKU
10) Peter Kelamis - I don't think I need to explain why he's at the bottom.