I think Arcade would be easy to do but because of all the help from old threads, FPS would be a good way to go.

Making a car one like Doug says can be a whole heap of fun as when you have everything working well you'd probably want to make different tracks and environments which is great for increasing your skill range as each new level would probably promt you to add more assetts that may need more scripts, then competitors (AI), environment and so on.

I started with FPS and I'm still stuck in learning mode!