I'm from the UK too!! I live not far from the centre of London in the eastend. My fave place for handbag shopping has to be Libertys behind Oxford Circus. They stock Luella, Chloe, Marc Jacobs, McQueen, Miu Miu, Mulberry and a host of smaller labels like Anya Hindmarch, Kimchi and Lulu Guiness. The shop assistants are so friendly and never rude or patronising. They also have high end vintage which I love to look at as I am a vintage queen ( never buy them there tho' - v. overpriced, markets like portobello and Spitalfields are better.) Harvey Nicks does have a great bag dept. tho' and i love looking at the Bracher Emden bags in Selfridges, though in general i find the assistants a bit off there.
As for my favourite bag - agghhh! How to choose! I love them all! I have a little cream chanel with gold chain that I picked up at a vintage shop that i'm carrying a lot at the moment and my Mulberry Araline too.
It's so nice to hear from other UK'ers, I was wondering how many of us are regulars here!