Two NBA championship games between the Los Angeles Lakers and the Boston Celtics scored big in the ratings for last week, but Gary Hart-breaker Donna Rice didn't, the A. C. Nielsen Co. reported Tuesday. Game 5 was the fifth most-watched program, with Game 4 right behind in sixth place. Game 6, which gave the Lakers the world crown on Sunday afternoon, was not reflected in these ratings, which cover only prime-time programs. NBC's repeat of the "Forgive Us Our Debts" episode of "Miami Vice," which fleetingly featured Rice, scored a meager 12.6 rating to rank 29th among the week's prime-time offerings. The week before, a Rice-less "Vice" nabbed a 14.1 rating and was in 22nd place. The top 10 shows were (in order) "Family Ties," "The Cosby Show," "Cheers," "Growing Pains," NBA Games 5 and 4, "Murder, She Wrote," "Who's the Boss," "Deceptions" (part two) and "Golden Girls." Of the 67 programs on the chart, the bottom five were "Our World," "West 57th Street," "Dads," "Gung Ho" and "Wizard." NBC finished on top for the week, followed by CBS and ABC. The NBC "Nightly News," earning a 10.0 rating, also outpointed the opposition, with ABC at 9.6 and CBS at 9.5. The complete Nielsen list appears on Page 8.