New
#1
one good site for Virtual Machine images ( virtual appliance's ) Is Bitnami they have a very large selection, Ranging from pre built Forums, WordPress, Multimedia sever, Cloud storage, Nas storage and a lot more.
Another good place is https://www.turnkeylinux.org/all
The one I quoted is first one I have seen of it's kind. I used to make my own so I can reuse them after changing windows and don't have to actually reinstall them in VM. Last few upgrades before this last one always broke my VM Player and would have to reinstall it and Linuxes in it every time. 2 -3 distros and programs in them can take long time to set up.