For the past week, I've been attempting to create a new Altcoin to learn about cryptocurrency, which I thought it was ready, but turns out after I released it, the coin got mined through easily and people started running into issues.
SHA256 is tricky in initial stages, since people have these usb miners, so
you need to start with quite heavy difficulty.
In my opinion Scrypt or X11 are fine... the PoW algo is just the engine
that makes the coin move forward in time, but what makes coin unique are
features on the transaction level.
That being said, if you want to explore this aspect, I recommend looking
at Blakecoin or Woodcoin.