The District's 10 most valuable residential properties have all topped the $2 million mark for the first time, the city finance office reports.

The separate commercial buildings list, compiled from fiscal 1981 tax records, continues to be headed by L'Enfant Plaza, the office and commercial complex in Southwest that is assessed for a full value of $84.2 million.

Hillandale, the 42-acre former Archbold estate across from Georgetown University Hospital, took the top residential spot, up from second place among home sites last year. The D.C. Department of Finance and Revenue said the property at 3901 Reservoir Rd. NW, including the former Archbold family villa, was assessed at $5.9 million--prior to its subdivision into a town house complex. New houses there are now assessed individually and the Archibold estate is expected to drop off the top 10 list.

Second among residences at $5.7 million--moving up from fourth position last year--is 2500 Foxhall Rd. NW, formerly the home of the late Vice President Nelson Rockefeller. Eunice Kennedy Shriver now owns the house; the remainder of the estate has been turned into a luxury-home subdivision called Foxhall Crescents and houses there will be assessed separately in the future.

Hillwood, the 25-acre home of the late Marjorie Merriweather Post, was in the top spot last year, but fell to third place with an assessment of $5.4 million. Overlooking Rock Creek Park at 4155 Linnean Ave. NW, the estate has been a museum since 1977 but remains on the residential tax rolls.

The manor house and grounds at 1801 Foxhall Rd. NW were valued at $4.5 million, moving the property up to fourth place from last year's eighth position. The estate is owned by Elinor Brady, widow of Rear Adm. Parke H. Brady.

The property at 3029 Klingle St. NW belonging to the family of the late Sen. Millard E. Tydings (D-Md.) was valued at $4 million to take fourth place. The Tydings' estate was not listed last year, but has been on earlier lists.

A cooperative development of single-family homes on Battery Place NW moved down one spot to sixth position with a total assessment of $3.2 million.

The home of real estate heiress Gwendolyn Cafritz at 2209 Foxhall Rd. NW moved up from 10th place to seventh with an assessment of $2.9 million.

Property belonging to Marjorie and Laughlin Phillips at 2101 Foxhall Rd. NW made the list's eighth position with an assessment of $2.7 million. The Phillips' property was not listed last year.

A vacant tract at Massachusetts Avenue and 50th Street NW fell from fifth to ninth position. The property owned by W. C. and A. N. Miller Development Co. was tagged at $2.5 million.

Falling to the bottom of the list from the seventh position is the estate of art collector and retired insurance magnate David Lloyd Kreeger. The landmark house at 2401 Foxhall Rd. NW was designed by architect Philip Johnson. The parcel is valued at $2.2 million.

In addition to L'Enfant Plaza, other properties on the commercial/apartment list include:

* Watergate, the complex of cooperative apartments and commercial space on Virginia Avenue NW--$76.2 million.

* International Square, an office and commercial complex at 1810-1860 K St. NW--$49.1 million.

* Columbia Plaza, apartments and offices on Virginia Avenue NW--$44.9 million.

* Van Ness Center, apartments and offices at Van Ness Street and Connecticut Avenue NW--$44.3 million.

* The Nassif Building, an office facility at 400 Seventh St. SW--$42 million.

* The Washington Hilton hotel at Columbia Road and Connecticut Avenue NW--$40.4 million.

* Office building at 1800 M St. NW--$36.2 million.

* The Washington Post headquarters at 1150 15th St. NW--$35.5 million.

* The Hyatt Regency hotel at 400 New Jersey Ave. NW--$29.1 million. CAPTION: Picture, The L'Enfant Plaza complex has the highest commercial assessment in the city--$84.2 million. Photo by Gorchev & Gorchev