One of the most engrossing museums in London, full of unexpected pleasures from political cartoons, comic strips, caricatures and graphic novels. No politician or public figure is portrayed in anything like a flattering depiction and the wit and acidity is admirable. Not really suitable for children as much material is only comprehensible to adults.
http://www.cartoonmuseum.org/ 10 minutes both Holborn and Tottenham Court Road tubes