Which Omnimon would you say is the best one?

Now that people are getting their hands on Battle of Omni, what’s everyone’s opinions on our plethora of Omnimon? If I were to invest in a playset of one type of Omni, which would be the best one?

OG Omni. Alter S. New Omni. X antibody. Zwart. Zwart defeat.

Did I miss any?