A bit of a different one this week as this is technically a subscription service with a free-to-play option, but put down your pitchforks and hear me out!
BGA is a platform for playing board games online, and about half of the games I’m aware of IRL are available, from simple classics like Carcassonne and Yahtzee to multi-day slogs like Unconditional Surrender and Scythe. Some games are free for anyone to play, “premium” ones require that the person who starts the game is a paying member (but that means that one enthusiast can pay a few quid a month and invite their friends to play for free). There are rankings and tournaments if you want to take it seriously, or you can exclusively play solo or with friends.
Not everyone’s cup of tea, but still quite a cool site you can enjoy without paying.
Another good one with some different games: https://www.yucata.de
This website ruled during lockdowns. Cannot recommend this enough!