The first space probes to leave our Sol system, Pioneer 10 and 11,
kept transmitting from 1972 and 1972 to 2003 and 1995, respectively.

Voyager 1 and 2, both launched in the summer of 1977, are still
returning valuable data on the way outer Sol system and will probably
keep transmitting until 2025.

Solar orbiter Pioneer 6, launched in 1965, was still transmitting in 2000,
but I have not heard much about it since.

As for Mars craft, had there not been a message screwup in 1982, the
Viking 1 lander was expected to keep talking to Earth until 1994, almost
20 years after it first landed on the Red Planet. Of course it was
nuclear-powered.