Hi ody and welcome to the forum
You're right of course, that is one of the most asked questions, also one of the hardest to answer. I don't think it's ever about ideas on what you can sell, it's more about what are you able to sell?
For example, if you can afford to purchase iPhone and pads by the container load to ensure the best possible price, then sell them at a reduced margin to generate volume turnover, then I would suggest that as my number one option. If you can't afford to do that, then I would suggest staying away from those products because you will be competing against sellers who are doing just that.
So you see, it's never a straight forward question to answer. Given that you have that bronze ranking means you are doing something right : )