My opinion? Spread the love around. Don't give 5 Pokémon to one user, that's too much overkill. Most people are ecstatic to win just one :) As for what to give away, give away your favorites. Personalize it. When I had my 1000th post, I gave away a 6 IV Snover as the final prize (my favorite Pokémon). I think people like receiving things with a little touch of personal value to them. Congrats on hitting 1000!