I don't really see how *giving* likes is a contest. I like a lot of posts, if I like or agree with them, or laugh react if they make me laugh. I'm not competing with anyone to hand out the most likes, or liking things I think are stupid or wrong. Not playing favourites either, if someone I don't personally like gives good info, I like it. I enjoy if a post of mine gets a lots of likes, obviously, since it means people agree or found it useful or funny. But who cares about top scores or rankings? Every forum I've ever used has made a point of underlining that karma/rank/positive or negative ratings mean nothing, and don't have any real effect, so not to take them too seriously.
Right now the top people are Juice, NC and Viking. I don't think they're trying to manipulate anything?
But if giving too many likes is frowned upon, I will refrain.