All totals are U.S. box office only. SF and genre-related films in bold.
Title (Dist)….Reported Weekend Box Office….# of Engagements….Cumulative
1. The Dark Knight (Warner Bros.)….$75,166,466….4,366….$313,781,677
2. Step Brothers (Sony)….$30,940,732….3,094….$30,940,732
3. Mamma Mia! (Universal)….$17,746,725….2,990….$62,595,465
4. The X-Files: I Want to Believe (20th Century Fox)….$10,021,753….3,185….$10,021,753
5. Journey To The Center Of The Earth (Warner Bros.)….$9,717,217….2,688….$60,487,455
6. Hancock (Sony)….$8,311,123…. 3,309….$206,482,007
7. WALL-E (Disney)….$6,422,186….3,044….$195,308,076
8. Hellboy II: The Golden Army (Universal)….$5,100,305….3,018….$66,059,925
9. Space Chimps (20th Century Fox)….$4,536,838….2,538….$16,167,380
10. Wanted (Universal)….$2,738,550….1,754….$128,627,405
Data provided by Rentrak
X Files was great. This is a tragedy.
X-Files might be great but it is up against Dark Knight. Generally people aren't going to go to more than one movie a weekend.