If it's for the missus just to potter around in and performance, or looks, isn't a factor, but reliability and running costs are, I'd say it's gotta be the mk7 Civic (2001-2005). Surprising amount of space inside, nice enough to drive, nippy little thing, and Honda's famed reliability

Pick up a 1.4 or 1.6 for circa £2k, preferably buy one off an old couple so you know it's most likely to have been serviced instead of ragged