V Gundam is IMO the best UC series next to Zeta. It takes place 30 years after Char's Counter-Attack, and it features 2 new groups at war with each other, Feddies are still there to some extent, but no-more Zeeks(if you get this reference you get a gold star)

ZZ is another story. It starts only hours after the last battle in Zeta, which was pretty neat idea. The first 25+/- episodes aren't directed by Tomino, and they are comedic and kinda iffy. However once Tomino takes over the series becomes pretty good. You also get to find out what happens to Camille after Zeta. Overall it's a decent series(better than destiny). If you want you can skip this and just watch Char's CA, you won't miss out on anything.