>>17976285 (OP)
For the British it was Malaya, Singapore and probably Hong Kong. They provided important materials(rubber, minerals), had important strategic location or served as trade and outsourcing hubs, respectively. Obviously Suez as well but Egypt in general was a bit meh, you could just buy cotton from them without having to spend effort policing the colony.
For the French Algeria for sure. Not because of some particular material boon(oil fields weren't exploited until after ww2) but because the extent of colonisation of it's northern coast, in many ways it was the Lebensraum for them. Indochina was also really profitable because, you guessed it - rubber.
German and Italian colonies were worthless no idea why they even bothered.
For the Portuguese, throughout their existence Goa and Macau provided the best bang for the buck. They were never really contested by the locals outside of few exceptions and they just printed money by being export ports. Brazil required lots of people to settle it and Portugal never had enough of people in general which stunted its development.
While everyone thinks of the big gold and silver colonies when we think about Spain, their Carribbean sugar producing possessions like Cuba were just as valuable if not more because sugar had lots of uses and gold especially at the time was just a token to exchange for other goods.
The Dutch were probably the masters of getting lots of value for relatively little when it came go colonisation. Indonesia became a goldmine due to oil, Curacao and other Carribbean colonies were consistently useful sugar producers, New York/Amsterdam was again very profitable.
