All totals are U.S. box office only. SF and genre-related films in bold.
Title (Dist)…. Reported Weekend Box Office….Engagements….Cumulative
1. Baby Mama (Universal)….$17,407,110….2,543….$17,407,110
2. Harold And Kumar Escape From Guantanamo (Warner Bros.)….$14,908,404….2,510….$14,908,404
3. The Forbidden Kingdom (Lionsgate)….$11,212,364….3,151….$38,237,498
4. Forgetting Sarah Marshall (Universal)….$11,028,060….2,799….$35,090,955
5. Nim’s Island (20th Century Fox)….$4,548,792….2,977….$38,977,518
6. Prom Night (Sony)….$4,508,122….2,821….$38,222,732
7. 21 (Sony)….$4,018,064….2,952….$75,792,625
8. 88 Minutes (Sony)….$3,593,890….2,168….$12,625,951
9. Horton Hears A Who (20th Century Fox)….$2,486,903….2,159….$147,959,806
10. Deception (20th Century Fox)….$2,312,146….2,001….$2,312,146
Source: Variety Data provided by Rentrak

Sad thing is, I don’t know what about half of those movies are. Only two I want to se are Nim’s Island (Definitely) and 88 Minutes (possibly).