Aidou is definitely not much of a gift person...unless he's getting them. XD
Kaname-sama: His soul...but wait, he already has that. A private dinner for he and Yuuki personally cooked and set up by Aidou? who will then go off and cry himself to sleep, but at least it may make Kaname-sama happy?
Yuuki: A book on "How to behave accordingly when you are the most important thing in the world to Kaname-sama and therefore should obviously take better care of yourself but don't know how"...For Dummies.
Zero: An ice steak to the chest...maybe. Depends on if he's been mean to Kaname-sama lately or not which is probably a yes.
Ichiru: ...he doesn't like you at all, but if it will get Zero out of Kaname-sama's hair A nicely tied up Zero with a red bow that Ichiru can do whatever he wants with.
Spike: Hmm...The guy wouldn't even appreciate it...A prototype of the new blood-based foods Aidou is making to see if that let's him eat regular foods too instead of surviving on blood only? Which really he was designing for himself and Yuuki at first, but if it helps the other vampires, then that proves what a good idea it was.
Lenalee: A freshly cooked breakfast with eggs in a basket, and assorted fruit pastries, and a new outfit with a longer skirt so she won't be as cold but she can keep his jacket it she'd like.