I LOVE the British Library. It's amazing - I swear they seem to have every book that exists on the planet there ! I've never been disappointed. The only snag is that it can get pretty busy... and due to tight security measures, it's a bit of a hassle locking your stuff in the locker downstairs, putting your laptop into a see-through plastic bag, basically there are loads of rules you have to follow, and if you dare to break them, you might be banned from ever returning. Like if you dare to make notes with a pen instead of a pencil. They're pretty protective of their darling books, so makes sure you're in an angelic mood before setting foot inside any of the reading rooms !