Florian Koebisch
Google
It's more like a bar and not like the standard museum café you'd expect.
They have a fantastic beer selection, mostly from small independent UK breweries plus great cocktails and wines.
If you're lucky, you can sit in one of the lounge chairs and enjoy a fantastic view of St Paul's and the river Thames. The interior feels modern and comfy, it's quite spacious and they are usually open until late, long after the museum closes.
It's actually one of my favourite 'riverside pubs'.