Washington didn't fare too badly in the 1985 listing of "Parties of the Year," as determined by Vanity Fair magazine, the smart, sophisticated publication that seems to have more fun than other magazines. Not surprisingly, the best party of the first month of 1985 was President Reagan's intimate lunch for 50 of his friends Jan. 20 at the White House following the private swearing-in ceremony for his second term.

Another party on the list was the June 24 Kennedy Library Foundation fundraiser in a tent at the McLean home of Sen. Edward Kennedy with a guest list that included a passel of Kennedys, including Jacqueline Onassis, and President and Nancy Reagan. And, as might be expected, two of the parties surrounding the "Treasure Houses of Britain" exhibit were listed. One was the Oct. 30 dinner at the Ritz-Carlton hotel for the "Magnificent Seven" owners of the great British houses that had American guests fawning over all those titled Brits. The other was the Nov. 9 White House dinner for Prince Charles and Princess Diana with all those show business celebrities, such as John Travolta, Tom Selleck and Clint Eastwood.

One of the truly great parties of the year, according to the magazine, was given the geographic location "Powersville." It was television quizzer Barbara Walters' party at New York's Le Cirque for Henry Kissinger, which brought out such guests as Robert McNamara, Winston and Bette Lord, Mike Wallace and Rupert and Anna Murdoch. The Plaid Jacket Power Crowd

It's best-dressed-list time again and guess what? President Reagan is on the list once again, plaid jacket and all. It's his third time on the list and as long as he's in the White House, he'll undoubtedly continue to make it. Also on the list, of course, is Prince Charles, who's valiantly trying to bring back the double-breasted-suit look. This look reportedly is influencing the yuppies of the world. But then, most anything does.

Others making the list were baseball commissioner Peter Ueberroth; former senator John Tower; actor Jason Robards; pianist Bobby Short; Trans World Corp. head Charles Bradshaw; WCBS-TV, New York, anchorman Rolland Smith; WOR, New York, radio announcer John Gambling; Jersey City Mayor Anthony Cucci; and . . . AND . . . hold on to your hats, singer Boy George. George was not cited for the women's clothing he wears but for turning young people to bright colors and dramatic hair styles. Any list with Prince Charles and Boy George on it can truly be said to cover a fairly wide range. End Notes

If you were after your usual Little Tavern hamburger last night at the one on North Capitol Street, you were out of luck. The black-tie crowd that had taken over the place was celebrating Rep. Dan Glickman's 41st birthday. Some people will go all out for a congressman. Look out Ritz-Carlton, this could be a trend . . .

Alas! Washington is that kind of town. At the intermission of Verdi's "Un ballo in maschera" at the Kennedy Center yesterday, Martin Feinstein, the Washington Opera's general director, announced to his audience that the Redskins had defeated the Steelers. And the audience applauded in approval . . .

An update on Joan Specter's stolen $4,000 sable-lined raincoat. The Philadephia city councilwoman's coat was stolen from her Nov. 15 while she was sitting in a Philadelphia theater watching a movie with her husband, Sen. Arlen Specter. A 22-year-old man was arrested on felony charges and Specter's coat was returned to her Friday . . .

There will be a memorial service tomorrow at 10 a.m. in the Music Room at the Phillips Collection for Thomas V. Downing, one of the last of the Washington Color School artists, who died last month. Among the speakers will be fellow artists Leon Berkowitz, Sam Gilliam and Paul Reed, Washington Post art critic Paul Richard and attorney Ira Lowe . . .