(From recent readings.)
Lavie Tidhar's The Bookman promises to be the first of a trilogy. In feeling, it harks back to K.W. Jeter's Morlock Night and Infernal Devices -- it feels more like dark, imaginative, slightly nutty science fiction than anything that is self-consciously "steampunk" (contrast with Cherie Priest's Clockwork Century books, for instance). Alien lizards rule the earth (and have since they took over from the Tudors) and are resisted by a coterie of literary lights (Karl Marx, Mrs. Beeton, etc.) possibly allied with a mysterious giant caterpillarish being called the Bookman. Wild, fun, and full of steamy goodness, yes (multiple lifelike automata, a submarine piloted by Jules Verne, etc.).
The most steampunktacular thing about Paolo Bacigalupi's The Wind-up Girl is its title, which falsely promises clockwork beings. But the title character is the creation of genetic rather than mechanical engineering, and though Bacigalupi head-fakes in other steampunky directions with his low-gasoline world powered by kink-springs and genetically kluged megadonts, he never quite gets there. I want to mention him anyway, because what he's done (some have called this "ecopunk") is a cousin to Steampunk and Cyberpunk, and because I found his milieu thoroughly engaging and detailed. I felt like I was reading James Clavell, only darker and dirtier.