[quote=@Demon Shinobi]
<Snipped quote by Demous>

Well for right now... I'm gonna say that Shaman King counts as complete cause it's sequel features all knew characters and so far doesn't revolve around the original cast. 
However, something like lets say Rosario+Vampire wouldn't count because the "sequel" It technically just continuing where things in the first part left off. 

Also do you mean best objectively, or best as in my favorite?
[/quote]

Mine was kind of a combination. It wasn't completely objective but how much I liked them did play a factor. I would have a completely different 2 and 3 it it was completely based on favorites.