at Kongregate.com (that's where I found my favourite tower games)
It's a browser game where you are a shopkeeper and have to make decisions to keep yourself in business. Seems to have quite a high player population for a what I call a teeny game. Pretty neat, check it out if you are into that kind of thing.
You can buy tokens with real money for perks, like most games these days, but can have a decent bit of fun without having to do that.