Zoids New Century Zero is the second season of zoids stateside. It should be known however that Century Zero, and its prequel, Chaotic Century, are very different.
Chaotic Century is more like your average action anime with a decent amount of drama and fighting. and OK characters- not too memorable, not too forgettable.
New Century Zero leans more towards cartoon on a story basis- battle after battle, hardly any plot twists or drama whatsoever, although the humor is typical anime humor- which in this case is quite amusing. And don't be deterred by the lack of story because the action is great- better than chaotic century I'd say - and characters such as Bit Cloud and Harry Champ are wildly entertaining, and almost impossible to forget. Also the soundtrack is amazing, blows away that of its predecessor Chaotic Century.
There is also a third stateside season of Zoids, Zoids Fuzors, which is my opinion is trash- it is very childish, and tarnishes the reputation of memorable zoids such as the Liger Zero and Berserk Fury. The Zoids appear to be more cell-shaded, and the fusion zoids look terrible as well- the CG is also a mess, the 3D cars are done so bad you'll laugh. Even the drawn animation is choppy. The Soundtrack is equally awful.
In my opinion Zoids New Century Zero is a great Anime and the Zoids you should watch if you must choose between the various seasons. However there are many who would say that Chaotic Century was better, i think we can all agree that Zoids Fuzors should have never been made
