I’m not really a pianist either, but had lessons when I was little and can play some. I taught myself to play Watermark by Enya and that’s my favourite. I also like to play Over the Rainbow.
A fun piece to play that is slowly getting on my family’s nerves is Maple Leaf Rag.
I also love playing pieces from my favourite movies, especially musicals. My friend’s favourite movie is The Notebook, so I learnt how to play the main theme for her birthday.