I used to play games on Popcap before they were bought by EA. Bejewelled, Peggle, and Plants Vs. Zombies are some of the best ones.
A little less known one that I really loved is called Seven Seas. It’s a very basic strategy game. You’re a ship in the ocean, on a grid, and there are a number of pirate ships. You move or shoot, and each turn you take, they advance towards you.
One of my favourites was always Mystery of Time and Space (MOTAS), a really cool “escape the room” style game. Not sure if it’s still playable anywhere these days but it’s great.
I also loved Shockwave stuff. Most of it you could download as visible cartridges to use in ShockMachine downloaded to your PC. Shockwave Tetris was great and had amazing music. There were also a bunch of South Park games like make your own Mr Hankey.
I always got a kick out of some darker mini games available on JoeCartoon (frog in a blender, hamster in a microwave) and ZooAss (kick the kitty). StickDeath had some good stuff too.