Mine was an IBM XT.

Later we got an IBM 386 with dos and 4mb of ram - it could play wheel of fortune. woot!.

My first windows machine was a Leading Edge 486SX-25 w/4mb ram and a 250mb seagate harddrive. It came with windows 3.1 and I later managed to shove Windows 95 onto it when it became available. Had to upgrade the ram when I got the game Mortal Kombat. (not sure which version). anyway - it wouldn't run on 4mb of ram.) upgraded the machine to a 486 DX-100 overclocked to 120 w/16mb of ram, and later to a 586 125 overclocked to 150 w/32mb of ram. Still have the machine today - it is churning along with an early distro of redhat on it.