The city and borough of Westminster is best known for is civic and government connections, but there a ton of major museums, including several with potentially nerdy exhibitions at any given time like the London Film and the London Transport museums.
Additionally, it borders Camden, with its nerdy bounty.
Orbital Comics: Comics shop and gallery.
Gosh Comics: Soho comic book shop and gallery
Foyles: Flagship bookstore, with café
Oxfam Bookshop Victoria: Charity bookshop
Madame Tussauds: Original location of the famous wax museum