Make up your mind, decide to walk with me

Science fiction is by definition nerdy. Even full kickin' sci-fi geeks will look down on alternate history, which is often for military sci-fi geeks with lots of minute battle description. Now I myself like alternate history as it is often entertaining. Lots of it does suck though. A few years back Robert Conroy wrote 1901, which assumes the Germans try to snatch the US gains from the Spanish American war. When the US says no, the Germans invade Long Island. Sounds crazy, but if you like this sort of thing, it is pretty fun. Conroy is back with 1862 which imagines the British joining the Confederates in fighting the US of A.

The Civil War is a perrenial favorite of alternate history writers. Harry Turtledove has an multivolume history that assumes the USA and CSA fight out WW1 and WW2 on North American soil. This one is really for die hards as it is looooonnngggg and drags terribly. Bring the Jubilee is a more literary (and short) approach to the topic.

For something more cheeky, check out Kim Newman's Anno Dracula. It assumes that vampires are real and that they "won" in Stoker's Dracula. Now they have take over the British upper classes. The social satire elements are obvious. It's in cheapie paperback too.