Actually you really don't want to watch Macross/Robotech just because of Macross Zero, because Macross Zero really doesn't follow the story at all. The themes are the same, but they really went back and changed a lot of story fundaments.

How can you like Macross Zero but not Macross? Macross Zero is really icing on the cake, but original Macross/Robotech will always be a classic.

It's really complicated, there's actually several series with the Macross title. At a point in time the first 26 americanized episodes were billed at Macross, but lated changed to Robotech (not sure when, but if you buy the DVDS they're all called Robotech now). I'd really recommend just watching the first 26 of the american version and bypass the japanese versions, unless you become more interested in robotech.

Another robotech OAV you might want to check out (if you liked Zero), is Macross Plus.

-take