In the 1950s the prospect of Malta being integrated into the UK fully (in the same way that french guiana is for france or hawaii is for the usa) and having maltese politicians hold seats in the House of Commons was seriously considered. There was a referendum held in malta and a debate held in westminister both of which were largely in favour in it until political instability in malta led to it being dismissed as an option.
What I don't understand, and want explained, is why was this on the table for Malta and not for anyone else (such as the Isle of Man, Gibraltar and the Channel Islands most obviously but also say Cyprus, Newfoundland, Jamaica, Belize, Singapore etc)?
In the years following the Second World War, the United States and the Soviet Union placed a great deal of pressure upon the European colonial powers to begin decolonization in accordance with Atlantic Charter. The first major crown colony to go was India, whose division and independence was contentious and poorly executed. As India began the painful process of partition along ethnic lines -- Burma (1937), India (1947), Pakistan (1947), Ceylon (1948) -- new questions about the precise status and options for decolonization kept cropping up as these nations rejected the dominion-status boiler plate so popular prior to the conclusion of the war. As early as 1947, Nehru invoked some precedence for Malta by offering Anglo-Indians the Andoman and Nicobar Islands in exchange for departure from India. The plan ultimately came to nought after Nehru's would-be settlers demurred and emigrated to Britain and the Commonwealth realms instead. (Source)
Malta was a particularly interesting problem for the Foreign Office. Malta was a prime candidate for dominion status. The population was entirely white and the island was relatively prosperous. However, two concerns consistently prevented Malta from achieving independence.
The first concern was defense policy. The War Office had long considered Malta an important source of power projection in the Mediterranean and they were leery of relinquishing control. In the last war, the island had been christened "Fortress Malta" and the British used the colony to torment the Axis in both Italy and North Africa. The War Office was also loathe to give up Malta because of other regional concerns: Gibraltar was the gateway to the Mediterranean, but far from flashpoints. Cyprus could provide coverage, but the Greeks had long clamored for enosis. Malta would offer the best chance for comprehensive defense.
The second concern was economic policy. While Malta was reasonably prosperous, it had been unable to cover its own costs for centuries. The island had long relied on aid from foreign powers since its demise as a serious trading outpost, resulting in a population tethered to the defense industry. The incompetent actions of the Maltese Government were also of some concern. Despite having inherited a budget with no debt and a 20mm+ GBP surplus, the local authorities consistently overspent a great deal of money in order to ensure popularity with voters. When the island wasn't teetering on the brink of bankruptcy, it was begging for aid, leading the home office to ultimately conclude that dominion status was impossible.
Dom Mintoff was the first politician to seriously advocate for a third, integrationalist option. Earlier discussions had toyed with the idea of Malta joining the United Kingdom, but with a status akin to a crown dependency like Jersey or Man. This solution pleased no one. The 1955 Round Table Talks changed that by introducing a novel concept: a full integration into the United Kingdom. Malta would have home rule but, uniquely, would also return a Member of Parliament to the House of Commons in Westminster. In this respect, Malta would resemble Northern Ireland which had both a local legislative assembly and national representation. (Source)
Various members of HM Government had a split reaction to Mintoff's proposal. Macmillan was elated. Lennox-Boyd was not. The Round Table Talks certainly appealed to British patriotism but at a cost: the United Kingdom would, in essence, be spending even more in Malta than it had already once the island joined the nation's social welfare schemes. Mintoff's overture was therefore not one of loyalty to the Crown but of very clever financial pragmatism. Negotiations lasted until 1958, but the 5,000,000 debt ceiling ultimately skewered the deal. By 1960, the defense landscape had changed and the British simply found no benefit in going into debt over Malta.
The reason why Malta was given this particular status is because the Maltese proposed it. Talks with other nations failed to come to this conclusion for a variety of reasons but the leading reason was a reliance upon boiler-plate independence with dominion status. A quick summary for the other former colonies you listed:
Crown dependencies: The crown dependencies have long had a distinct and proud identity from the United Kingdom. In the years following the Second World War, taxation became a major issue as these islands had unique benefits: one could do anything they wanted in the Mainland but still escape the onerous duties owed to the Exchequer.
Bermuda/Gibraltar: These two colonies had a strong dependence on the defense industry like Malta. Both, however, had a fairly strong loyalist base and no push factor towards independence.
Cyprus: Cyprus was highly divided and was in strong favor of enosis until the Turkish resettlement in Northern Cyprus. The Foreign Office had no desire to get involved in a regional conflict between two allies but did wish to keep the Mediterranean power projection lost in Malta, thereby creating Akirotiri and Dhekelia.
Newfoundland: The Canadians would have had a fit had Newfoundland not joined the Confederation because of an integrationist plan spearheaded by London
Jamaica/Belize: No substantiative cultural links
Singapore: Integration would have caused a conflict with Malaysia and no one particularly wanted integration.
Basically, at the time, Malta was still important to the UK as a naval base. The UK was still considered a "superpower" at the time. Also, the Maltese general election was won with the Maltese Labour Party with an overall majority, and their manifesto was based on either independence, or full integration with the UK.
The reason other territories were not offered this is because it was not considered favourable on both sides. The people in the current Crown Dependencies and Overseas Territories are protected by their constitutions, and integration could just cause tension (see: Gibraltar, Falklands).
Newfoundland was basically manipulated in to joining Canada, given Canada was the oldest colony, and a supporter of the UK (at the time). Other nations were not offered the same because the UK was worried on how they would effect the outcome of elections.
The other time they tried this was the "Imperial Federation", which would have united the British Isles, Canada, Newfoundland, Australia, New Zealand and some other island colonies.