Dwarf Fortress was the original inspiration for Minecraft. Notch said he originally wanted to make a game like Dwarf Fortress but with isometric graphics. The blocky graphics and first-person perspective are the part that were inspired by Infiniminer.
Dwarf Fortress can be found via Google and is available for free (it's also in alpha, and the developer lives off of donations), but I'm warning you it takes a while to figure it out. I like it a lot better than Minecraft because it's much, much more complex (it's been in development for about eight years now).