If I'm right the only actor who was in both the movie and the TV series was Gary Rich Burghoff, who played Radar O'Reilly. I enjoyed the series far more than the movie.
A few actors from the movie made guest appearances on the TV show, but he was the only one to play the same regular character. I remember one episode where he kept sending parcels home, and Hawkeye and Trapper were curious as to what was in them, so they got hold of one and X rayed it. He was sending a jeep home in pieces.