The Wellcome Collection hasn't been open for very long, but it hasn't put a foot wrong yet. Upstairs is a bonkers anthropological collection, a bit like the Pitt-Rivers Museum but with waaaay more money. Downstairs they've had a succession of ace exhibitions; lately, "Life Before Death" has had all the press (and deservedly so), but "From Atoms to Patterns" is more fascinating. It's about crystallography, art, design and the Festival of Britain... oh, just go and see it if you're passing by, you won't regret it.
Islington also has a new museum, though this is probably of no interest unless you live here. Still, it's a big step up from the previous "museum" (two rooms in the town hall), so yay for the
Lastly, there is officially no such thing as too many Leonard Cohen covers. MyOldKYHome hosts dozens of cover versions of Hallelujah alone, and there's even a whole article on the subject. Anyway, I now have an album of Hallelujahs: 42 versions of the same song, and they're different enough that I can listen all the way through without getting sick of it. YMMV, I suppose.