Scrabble is, to me, a perfect game: the difficulty of the game increases as the individual player understands the game's limits; not necessarily the skill limit of the other player.
The first step to becoming good at scrabble is building a vocabulary-- but the longest word is not always the best word to play in a given context. As soon as a player has memorized enough 2 and 3 letter words then the game becomes purely spacial, more or less dominos with an incredibly complicated scoring structure. At a certain point a threshold is reached where a player memorizes the tile distribution, and begins to compute the basic probabilities of their opponents' tiles, and then the probabilities of future tile placements. In essence, Scrabble is a game of ever-increasing limits and the beauty of that is that the only real opponent is the game itself.
Obviously, it's incredibly difficult to find people to play with me. It's the one game where I'm genuinely more excited when I lose than I am when I win because that means that someone else is thinking about Scrabble just as hard as I am, and that there's glaring evidence that I can improve.