R2 woops T3. No one can say otherwise.
I'd give HK-47 the win, only due to his originality. As far as I know, the 50's are just as good as him. As far as I know.
I don't know who 4-LOM is.
From what I remember of Galactic Battlegrounds, OOM-9 was a commander, so he doesn't fair well against a Bounty Hunter Droid.
I don't anything about IG-72.
GO-TO. Honestly, a cutting laser against GO-TO?
I consider Palpatine to be the same as Chuck Norris. Only because if he kept up the Lightning barrage against Mace, his "force mask" would have melted down to a face befitting a god with a beard that cuts through adamantium. Which is why Palpatine>Revan and Bane. Take that Great Vengeance's/Nebaris' beliefs.