My first was at work, used to code the robotic PCB assembly tools. I remember getting xtree-gold and wow'ing at the graphical folder interface !
Amstrad PC1512
CPU: Intel 8086 @ 8 MHz
Usable RAM: 512K (PC1512), 640K (PC1640)
Built-in ROM: 16K
Graphics: MDA, CGA (PC1512), MDA, Hercules...