I started doing genealogy as my hobby and that took a lot of my free time to do research at historical societies, on the internet, interviewing relatives, sending out research requests, making a documented database of my findings to support my research. But I love detail work so it was fun.

I also started a salt water fish tank and that took time, research, and continuing upkeep. Plus watching the fish in my reef tank was always fascinating (and relaxing).

The other suggestions are good ones. Dimpled One, I'm going to have to look up that book. I've been reading Weis & Hickman's Dragonlance series and also Naomi Novik's books.