>Original Series
Just a great cartoon. In typical capeshit fashion it can sway from silly to serious, aimed at a lower age group than Batman or Justice League but still easily watchable. I think a lot of fans were hoping Ben 10 would become a bit more "mature", but that later resulted in the shit show that was AF/UA.
Best opening theme.
>Alien Force/Ultimate Alien
Identity crisis cluster-fuck that flip flops around and doesn't seem to know what it wants to be.
First half of season 1 makes the mistake of being "too cool for magic", so everyone is alien hybrid offspring and Gwen is treated like a fucking idiot who thinks Hogwarts is real. It's much edgier, but that almost highlights how it's inherently stupidly childish.
Ben has a bland stock stoic personality but calls out the names of the aliens he transforms into like a Pokemon (and rarely turns into OS aliens because they have to sell toys of their lame straight upgrade counterparts).
They have issues understanding Ben's character, even when they use kid Ben he is much more spiteful than in OS. Also they are terrible at writing romance. Did introduce some good characters through.
>Omniverse
Big return to the style of the original series, much more lighthearted and humorous. Ben is back to kind of an easy-going arrogance, generally more likable because he mostly brags about himself rather than shit on the people who do nothing but help him. Most of the new alien designs are weak, but it makes up for it by using older ones just as frequently and having the fucking taste to go with XLR8 over Fasttrack.
People bitch about the art style but I don't mind it, I don't know if I'm just desensitized because of the way stuff often looks in current year.
Petered off in later episodes and fell into the trap of waifushit, romance is still poorly written.
>Reboot
Reverse issue of AF/UA, this shit is for distracting babies and there's no defending this art style or what they did to Uncle Max.