What retro consoles still have the most active game development? The most games still being released physically? The best and most popular time-tested consoles?

I'm excited to start learning programming and had a thought to make a game (having an objective makes it easier to learn). I wrote up an entire plan already for the mechanics and it seems incredibly viable for a fun and full experience. I would like to have it playable on real hardware and am just trying to figure out which system to make it for.