Savage 2: I’ve been meaning to play this more. It’s the sequel to the semi-neat Savage game of yesteryear. Basically, it’s half FPS, half RTS. Also $20, also native on Linux.
San Juan: This one is a board game. The sequel to the popular game Puerto Rico, this distills the complexities of that game into one of the most elegant games I’ve played in a while. It manages to use one deck of cards as both money, trade goods, and buildings. Very quick too, taking only about 30-45 minutes.