I have Mini itx size pc if any random coins still use gpu mining, otherwise I thought perhaps a Raspberry and usb miner like Antminer U3 etc.
Is there any coins that are not too difficult to mine and is not totally volatile? As stated I'm not looking to make profits, just experience budget mining and see something in a wallet and I would like it keep is small and quiet like a raspberry project etc.
GPU mining is still very much alive... not very well however.
To mine on the cheap, nothing beats GPUs, especially if you already have a decent one in your processor!
Try multi-algo coins. Install wallet once, play with multiple algos. MyriadCoin is currently quite low diff, odds are you might hit a few blocks even without joining a pool (not that I suggest to solo-mine). Digibyte is also multi-algo now but diff is high.