Back to Malta, I did a week in Malta, and found it interesting. That said, I was pretty stressed out at the time, and really was focused more on de-stressing and relaxing, but I did visit a number of the tourist sites. I didn't do any of the ferry trips (Gozo or Sicily), so I think if you included them, you could definitely fill up an active week.

Valletta, Rabat and Mdina were definitely worth seeing. Mdina includes the St. Paul's Catacombs, which are worth an hour.

I wrote about my trip to Malta in my blog here -> Land of Goat's Milk and Honey

I flew out of Gatwick on EasyJet.

Cheers,
Greg