I was wondering if anyone knows where Evil Genius stores its savegame files. I like to keep a backup of all of my savegames so that if I end up having to do a reinstall/upgrade and have to restore the game, I can go back to my previous savegames. Unfortunately, so far I haven't been able to figure out where Evil Genius sticks them.

You might aswell backup the files mentioned by Ralackk just to make sure, but the files you definitely need to backup are the .lay files in the layouts folder, which are the actual savegames. The other files are generated alongside the .lay files with each save but i don't think they are essential.
I just downloaded the savegames available on Evil Planet (Alexis, Normal Difficulty) and i only got a folder with the .lay files, nothing else.
The savegames are on the downloads section, under 'others' on Evil Planet if you want to check them out for yourself.

If you are playing on Windows 7, you can find the saved files here.
C:\Users\(your user name)\AppData\Local\VirtualStore\Program Files (x86)\VUGames\Evil Genius\DynamicResources\Layouts
oh, and it works great, even on 64 bit.

Thanks for that bit about the windows 7 savegame location. I've been googling all over and haven't come up with anything except here.

there's no apps Data in my users area thing

It's a hidden directory. Go to /Users/(yourname) and click "Organize," then "Folder and Search Options." Click the "View" tab In the window that pops up and then check "show hidden files, folders and drives." You should be able to see the directory then.

Thanks

If you physically move the game (for example I've moved it from the C: drive to my G: drive) then it ceases to use the c:\user\<your name here>\AppData path and instead looks at the directories where the game now resides.

In my case those are G:\Rebellion\Evil Genius\DynamicResources\CodeGeneratedData and G:\Rebellion\Evil Genius\DynamicResources\Layouts.

This is what I've found for Windows 10. Also the game plays with absolutely no issues whatsoever. It's a cracking piece of work.