Any mobile suit that can hit a colony reactor could detonate the entire thing. Zaku's early in the One Year War were all equipped with nuclear bazookas, and roughly hald the human race as killed in a week's time. The most powerful Gundam from each series would be:
-There's a lot of debate on this one. Some may say it's the RX-93 Nu Gundam, or the F91 or the V2 Assault/Buster Gundam. You could also nominate the Ex-S Gundam or FA[E]ZZ Gundam as well. Then there's Xi Gundam from Hathaway's Flash, and probably a handful of others that could handle themselves well enough.
-No contest, Gundam XX wins here
-It's all between the God Gundam and the Devil Gundam, possibly Master Gundam as well.
-Gundam Epyon and Wing Gundam Zero are the powerhouses in this series.
-The Turn A Gundam, and possibly the most powerful mecha in all of Gundam if not in all of mecha anime.
Knight of Avalon
The World-Wide Gundam Informational Network
Sieg Zeon! Sieg Zeon! Sieg Zeon!
"The Nu Gundam isn't just for show!" - Capt. Amuro Ray, UC 0093