TI-99/4A (my first computer, 1984)
Commodore 64/128 (second and third computers, 1987 and 1990)
Amiga (my fourth computer, 1992)
Additionally, I had a brief flirtation with Apple ][s and Atari (due to school,) the later of which I am delving more into with a long-ago acquisition of an Atari 800XL with 1050 floppy drive, which I am not sure but may be Happy. There was period during which my 64 was dead and I was relegated to using a Vic-20, which, as neat as it may have been, I am likely not to enshrine in my collection. My grandfather had a 520ST, and I would love to assemble a beefed up ST system.
I have also in my time turned up an SX-64, of which I now have two. My family also had a Color Computer 3 for a very short while. I think we focused more on the 99/4A than on the CoCo3 so it had to go. A lot of other people have mentioned consoles, so I will mention that we only ever had an Atari 2600. Personally I have now garnered a 5200, 7800, NES, Genesis CD, Nomad, PlayStation, and an X-Box.
For now, I am content with my active 128D, 99/4A with peripheral expansion box (PEB,) several Amigas, and building up the Atari 800XL system. I will most likely also set up a 64C system once I get my room organized.