I actually almost forgot about that 🙂 Thankfully, I saved a few items to give him.

So far, C2-N2 (Republic Ship Droid) seems to like:
Republic Memorabilia – Liked the least (not counting stuff that gave 0)
Cultural Artifacts – Likes the most out of everything I tried
Technology – Liked the second most
Luxury – Tied with Republic Memorabilia

He does not like:
Weapons
Underworld Goods
Imperial Memorabilia
Courting
Trophy
Military Gear

Shall update as I test them out 🙂 All checked <3 I would guess the Imperial side would be similar, but with Imperial Memorabilia instead of Republic.