Good Old Games has a sale for Master of Magic!
There are other games on sale this weekend too. Patrician 1 & 2, Tropico and Tropic 3 among the others.
A classic - I still have this game (and Master of Orion I & II) on my PC.
It's brillaint, although do make sure to get the latest patch and read up on bugs. There are some spells that break the game.