Blackjack
An absolute classic.
This was probably the first project I ever "completed" - although there are a lot of features I would like to add in the future (for example, a gambling mechanic, saving the game, nice animations), I am pretty proud with how far I developed my coding skills over a short period of time.
Blackjack is one of the first projects of Scrimba's Frontend Developer course - if you are interested in learning about coding, you should definately check out Scrimba. They have a wide range of courses available, and an active community with regular coding challenges and livestreams. Their enthusiasm for teaching people around the world is inspiring, I can't recommend them highly enough!
Play Blackjack