Asaf Karagila has become the first to be on MSE for 1000 consecutive days. There is even a movie, Asaf of the Thousand Days, with Richard Burton, and Genevieve Bujold playing Asaf.
EDIT. The Guide For the Perplexed: Asaf is a male person living in Israel. He finished at Ben Gurion and is now at Hebrew University of Jerusalem. The movie took some liberties, for example, Bujold is French Canadian.