Apart from the obvious FRA, AMS, CDG and BRU are there any European cities one can fly to from MAN early in the morning and return late at night, for a good day trip? I would like to do DUB, but the flights seem to return too early to get an early evening meal in.
You can also add these three cities to the list 750XL gave:
DUS - flybe departure MAN 06:50 - arrival MAN 21:35
HAJ - flybe departure MAN 08:30 - arrival MAN 20:50
ZRH - Swiss departure MAN 08:40 - arrival MAN 18:10
Both DUS and ZRH have facilities for aviation enthusiasts!