Viewing facilities are available at Luqa Malta. Very good view of the runway from an elevated platform on the opposite side of the runway to the terminal. Viewing is also possible from the landside cafe on the top floor of the terminal. Not possible to see too much once you have gone airside.
A while since I was in Madeira but there was an open air balcony, cannot remember whether access was just from airside.
Have to agree with others, facilities in the UK are poor to non-existant.
Planemike