This list is also mirrored on Amazon
Fiction
Gail Carriger - Soulless
Alternate Victorian society with an empire and social system propped up by supernatural entities.
Susannah Clarke - Jonathan Strange & Mr Norrell
Victorian magicians leveraging the fairy world in their struggles for dominance.
Ian MacLeod - The Light Ages
An alternate England with an Industrial Revolution powered by 'aether'. Downtrodden underclass includes magical beings created as an offshoot of aetheric 'pollution'.
Tim Powers - On Stranger Tides
Pirates battle for the secret of eternal life. Right era, if wrong geographic setting. Especially noteworthy for Powers' ability to describe magic as a resource - existence, use & value.
Philip Pullman - His Dark Materials
A stratified, semi-Victorian society based on the control & manipulation of magical energy. Pullman famously gives magical resource a religious significance as well. The conclusion of Northern Lights, in which Lord Asrial is separating children from their familiars in order to harness magical energy - essential flowerpunk in both plot & tone.
Jonathan Stroud - The Bartimaeus Trilogy
Exceptional trilogy in which an oppressive Victorian magocracy maintains power by utilizing magical slaves. Told from alternating points of view - including a budding magician, a revolutionary and one of the enslaved djinn.
Michael Swanwick - The Iron Dragon's Daughter
Grim tale of an industrial fairy world.
Tad Williams - The War of the Flowers
Although initially set in the modern world, the bulk of the book takes place in a dystopian fairy world in which Victorian 'technology' is powered by the life-force of the fairy proletariat.
Gaming:
Privateer Press - The Iron Kingdoms RPG
Privateer have always eschewed the "steampunk" label, claiming that the Iron Kingdoms is "full-metal fantasy". Complicated magical system based on magically-charged, steam-powered 'mechanika'.
Victoriana RPG
"It is the year 1867, and it is a time of revolution. The new science has done more than bring incredible technologies into the homes of everyday people. It has brought with it a new way of looking at the world. A way based on observation and logic that threatens the ancient dogma of Aluminat church teachings..." (Recommended by @neverwhere)
Fantasy Flight - Sorcery and Steam
Surprisingly comprehensive supplement for the d20 system. Gets bogged down in airship-related prestige classes, but provides a lot of useful & imaginative detail for those looking to add steam-related technology & an urban setting to their campaigns.
Debatably Excluded:
J.K. Rowling - Harry Potter [modern era]
George RR Martin - Fevre Dream [vampires in the steam era, but this is "straightforward" historical fantasy]
