Venera
Lightning on Venus has been pretty well known since it was detected by sensors on the Venera-11 lander in 1978 and flashes were seen by the Venera-9 orbiter in 1975.
The Russians landed on Venus 10 times, flew balloons in its atmosphere, drilled into its surface and mapped it with synthetic aperture radar. But I doubt if we will see much mention of their work in the ESA press releases. It's particularly awkward to mention the 1975 Venera-9 and Venera-10 orbiters, since Fred Taylor has claimed that Pioneer Venus (1978) was the first satellite of Venus (see his article in The Century of Space Science, Kluwer 2001).