Gundam 00 is terrible, any big-time Gundam fan will tell you that. It's a waste of time, silly, and has all the worst parts of Gundam SEED infesting it like a pus-filled growth. There is only one good storyline in the entire series, Allelujah's, the rest are all fucking ridiculous. The most obnoxious part is everyone always uses everyone's full name, no matter how close they are to each other...including middle initials if they have them!
G Gundam is also kinda bad, but it is my favorite because it is so damn cheesy. It's fun, has no connection to anything else in the gundam multiverse, has good unit designs, and the sub and dub are both amazing. It's just fight after fight and
amazing levels of GAR.
If you want to start watching Gundam on a serious level, watch either
0079 or
Unicorn, then watch the other.
Do Not watch SEED.