In general, starting with the products you love to use, or looking at where your favorite people you've ever worked with currently work, is probably the best move.

In case helpful, I collected some startups I find interesting, see the startup lists section: https://chrisbarber.co/start-here/.

Though I think the ideal would be:

* What are the products you find most enjoyable to use?

* Of those, which ones do you have ideas for improvement based on your usage?

* Who are the best people you've ever worked with or collaborated with?

* Where do they work today?