Data flew the Enterprise around season one and two. He, Geordi, and Worf switched around at the beginning. He also reprised that roll in the past scenes of All Good Things.
I had always been under the impression that Conn and Ops switched sides after Encounter at Farpoint (and mistakenly during a number of episodes in Season 1) so Data was always Ops with La Forge at Conn (other than when Worf or O'Brien filled in).
Tough question really and I dont think I could poll a top 2 as Paris, Nog and both Sulu's would be contenders.