Here's where I keep a little retro flavor at work.
On the top shelf, I have (sealed for freshness!) copies of MS-DOS 5.0 and 6.22; Windows 3.0, 3.1, and 3.11 WfW Upgrade; Windows 95 and Plus!, Win 98 SE and Plus! 98, Win ME, Win 2000 Pro, Win XP Pro, Win Vista Ultimate, Win 7 Pro, and Win 8 Pro; and MS Visual C++ 4.0 and 6.0 Pro.
Next to that are (not sealed, but still fresh!) copies of OS X 10.0 Cheetah, 10.1 Puma, 10.2 Jaguar, 10.3 Panther, 10.4 Tiger, 10.5 Leopard (and 10.5.6, because I can't boot 10.5.0 on the Mac Mini).
The Mac Pro G4 Cube has OS X 10.0 through 10.4 on a 120GB SSD. The 2009 Mac Mini has 10.5 through 10.9 on a 320GB HDD (an SSD upgrade is in the works). I also have a 2012 Mac Mini with 10.10 - 10.14 on it, but it got repurposed as a multitrack recorder for band practices.

The Pro speakers (large round eyeballs) need to be repaired due to rotted foam surrounds. (They disintegrate with the slightest touch into a sticky goo.) I have some raw Aura drivers I think will fit. The Harmon / Kardon Sound Sticks also need some refurbishing -- mainly just disassembly, cleaning, and resealing where the adhesive and rubber isolation have started to break down.