XXX was actually topped last spring.
And 21 didn't even have top the opening for a vowelless title in March.
Here's the new list below (unadjusted for inflation).
Not counted are movies that really have two-part titles, like K-19: The Widowmaker; 2001: A Space Odyssey; or X2: X-Men United. Otherwise, X2 would top all contenders with its $85.5 million first weekend.
(1) 300 (2007) $70.9 million. Sparta's king shudda taken more guys into battle.
(2) XXX (2002) $44.5 million. Vin Diesel plays cross between Evil Knieval and James Bond with more tattoos.
(3) 10,000 B.C. (March 2008) $35.9 million. Back in the day when bringing home the bacon meant slabs of woolly mammoth meat. (May also tie for longest vowelless movie title ever, matching George Lucas' 1971 sci-fi debut, THX 1138.)
(4) TMNT (2007) $24.3 million. Although initialed, this wasn't the initial Teenage Mutant Ninja Turtles flick.
(5) 21 (2008) $23.7 million. MIT gang masters blackjack, beats the house, get beaten up.
(6) 1408 (2007) $20.6 million. John Cusack gets warned, still insists on staying in evil hotel room.
(7) 8MM (1999) $14.2 million. Nic Cage investigates a snuff film. And you thought it was a text message meaning "had a chocolate with a candy shell."
(8) K-9 (1989) $7.5 million. Cop-with-canine comedy starring Jim Belushi.
(9) 2010 (1984) $7.4 million. Sequel to 2001: A Space Odyssey.
(10) 54 (1998) $6.6 million. Drugs, dates and disco at famous New York club Studio 54.
(11) FX/2 (1991) Sequel to No. 15 below.
(12) JFK (1991) $5.2 million. Oliver Stone explores assassination conspiracy. Not Arlen Specter's favorite film.
(13) 48 HRS (1982) $4.4 million. Eddie Murphy-Nick Nolte cop-con hit.
(14) 10 (1979) $3.5 million. Dudley Moore goes gaga as Bo Derek embodies perfection.
(15) F/X (1986) $3.2 million. Special-effects thriller about a phony murder.
Also noteworthy for their titles (not so much their box office):
Single-letter titles: M, 1931 creepy Peter Lorre classic; Z, 1969 Costa-Gavras thriller; and the 1998 math-geek-freaks tale whose title was the Greek letter pi.
Title with a fraction: Fellini's 8-1/2 (1963) won best foreign-language Oscar.
Two more years: 1984 (1956), based on George Orwell's classic, and 1941 (1979), John Belushi-Dan Aykroyd stab at comedy about Californians fearing Japanese attack. With a $2.7 opening-weekend, it would likely make a Top 20 list.
CAN YOU THINK OF A MOVIE WE MISSED? Contact staff writer Peter Mucha at 215-854-4342 or pmucha@phillynews.com.