Please define "Gundam". I've seen that sentence asked were "Gundam" meant the individual Gundams from one series, from the entire Gundam-verse, or the series themselves. So I'm afraid I'm a little bit confused. sweatdrop
If we're referring to G Gundam, I'd say the Rose Gundam is the best because it turns the themed design into the most versatile offense and defense device in the Gundam Franchise.