Strangers' Hall, Norwich
Strangers' Hall is a compact and lovely museum depicting comfortable urban living in the 17th, 18th and 19th centuries, with many original artifacts.
It is not perhaps as exciting and interesting as the nearby Bridewell museum, or anywhere near as good as the similarly themed Christchurch Mansion Museum in Ipswich (to which, incidentally, admission is free - it isn't to Stranger's Hall). But on the other hand the Castle Museum is better than any museum in Ipswich.
The best thing about the museum is the intimacy - it is possible to get very close to tiny details. Oh, and the staff are nice, too.