TripleA - TripleA is a free (under GPL) turn based strategy game based on Axis & Allies board game.
Worms - Worms is a Superb, Turn-based, Strategy, Online, Single and Multiplayer video game developed and published by Team17 Software Ltd.
ThumbZilla - Awesome thumb stomping and kicking action game.
Worms Battlegrounds - Worms Battlegrounds is a Single and Multiplayer Turn-based Strategy video game developed and published by Team 17.
Warlight - Warzone is a customizable Risk-like strategy game where you compete with your friends to conquer the world.
Hedgewars - Hedgewars is a Free to play, Single-player and Turn-based Strategy video game developed by Hedgewars Development Team.