Usually set in the 19th century (where steam was the superpower), but containing elements of fantasy or science fiction, steampunk stuff features a lot of machinery with cogs, knobs, levers and most importantly steam. Think magnificent flying machines and infernal devices (courtesy of Philip Reeve, K W Jeter and soon, worryingly, Cassandra Clare)… Leonardo-type contraptions without the linseed oil.

1. Pride and Prejudice and Zombies, Jane Austen (who would have thought?) and Seth Grahame-Smith
2. Airman, Eoin Colfer
3. Larklight, Starcross and Mothstorm, Philip Reeve (children’s fiction)
4. Mortal Engines quartet, Philip Reeve (and now Fever Crumb)
5. The Sally Lockhart mysteries and His Dark Materials trilogy, Philip Pullman
6. Girl Genius, Kaja Foglio (graphic novel series)
7. Airborn, Skybreaker and Starclimber, Kenneth Oppel
8. Perdido Street Station (and Un Lun Dun), China Miéville
9. The Prestige, Christopher Priest
10. The Steampunk Trilogy, Paul Di Filippo

And some movies:

1. Howl’s Moving Castle
2. Van Helsing
3. The League of Extraordinary Gentlemen
4. The Prestige
5. Stardust

Interested in doing some research? Start by checking the links on the Wikipedia page.