I used VirtualBox to test Linux distributions at first. What I loved doing was install it, put it in full screen and use it one or two days the whole day using it for serious tasks and to mess around. Didn’t game on it of course because graphical capabilities in VMs are severely diminished. Thanks to this I found my true love being Debian, and I’ve been using it every day for 2 years after I’ve installed it outside of the VM.
I still do it but now I mess around in PCem with Windows 9x and pre-XP NT releases.