If anyone is planning to be in Malta this spring I'd recommend traveling in late April to coincide with the Malta International Fireworks Festival, which takes place on the 26th and 28th of April. The Grand Finale of the fireworks will be held in Valletta's Grand Harbour on April 30th. As far as best place to view the fireworks, Barriera Wharf (inside the Grand Harbour) is probably the best place to view all the action.
Best viewing spots for Malta's fireworks festival are your hotel balcony. Some hotels like the British hotel have a cool dining room balcony that offers amazing views.
I too agree that the British Hotel offers probably the best position for the Malta Fireworks Festival and their restaurant overlooks the Grand Harbour, which is where the fireworks take place.