I never win anything chance-related like lotteries and stuff, so I doubt I'm the 1.5 millionth person, but in that place I'm with Benjamin above... a simple personal hello and congratulations would be extraordinarily awesome. It's not like there are public hello's to an individual follower or fan floating around from many stars of +William Shatner
's level. I don't have much else to gauge by but what might float my own boat but that seems easy, cheap and for the follower, thoroughly satisfying and bragging rights to re-share on Google+/Facebook/etc! :) Gratzi, Mr. Shatner, for interacting with your followers and having fun with it.