Scrabble3D is a very configurable version of the classic Scrabble game which offers many interesting options.
You can play regular 2D Scrabble against the computer, with a local opponent, across your network or by connecting to a game server.
This default mode is straightforward to use. Click Game > New Game, choose the number of opponents and their type (#1 human, #2 computer, say), click OK and that's it. If you're playing against the computer then it'll make its first move immediately, your tiles are visible, and all you have to do is select, drag and drop them into position on the board.
If you need something more, there's support for SuperScrabble (a 21x21 square board), a 3D variation which allows you to play in 3D space, or you can build a custom game with your own choice of board size, colours, timeout and word check rules, joker options, difficulty levels and more.
There are also plenty of advanced options for Scrabble experts, including post-game analyses where the computer calculates the best possible moves.