My grandfather joined the RAF in 1928 and retired in the 1960s. His service overlapped my father's, who himself retired in 1992. I joined in 1990, retiring June 2012. I am a now a member of the Auxiliaries however in terms of continuous, full time service my family racked up about 84 years.
Of perhaps moderate interest is that my grandfather's first operational sqn was also my first operational sqn. Whilst on his second sqn he served in Iraq; exactly 70 years later I served on the same sqn in the same places in Iraq.
Fun fun fun.