The Tiny Fey-Amy Poehler comedy Baby Mama topped the weekend box office with $18.3 million, followed by the second adventure of Harold and Kumar with $14.6 million.

With a wider audience thanks to the PG-13 rating and the strength of a female demographic, Baby Mama lead all weekend, another success for “30 Rock” creator Tina Fey. This is the second-largest opening for producer and SNL show-runner Lorne Michaels behind Fey’s other project, Mean Girls.

Coming in second with a hardcore R-rating was Harold and Kumar Escape from Guantanamo Bay. The original only made $5 million on opening weekend and $18 million total domestically, so this sequel will easily surpass the theatrical success of White Castle. The budget for H&K2 was $12 million, so it has already made back its money and then some. That trilogy they talked about at SxSW Film Festival is looking very possible.

In third place for most of the weekend was Forgetting Sarah Marshall, but The Forbidden Kingdom barely beat it again for the second weekend in a row. Again, it’s PG-13 and much more kid-friendly than FSM’s full frontal male nudity. Kingdom made an estimated $11.2 million (a respectable 47.5% drop) and Marshall made just $11 million. Though the numbers could change when the finalized actual figures come out on Monday. I bet you can’t wait to find out. I’m know I’m excited. Feel these nipples.

Nim’s Island is still in the same spot as last week, fifth place, with $4.5 million. It’s $38 million has officially passed the $37 mil budget for the kiddie adventure. Abigail Breslin is worth more than you, get over it.

The only other opener was Deception, which its stars didn’t really promote. Fox only distributed it as a favor to Hugh Jackman. Which means there’s no way I’m sitting through that. Regular NiF reader and Hugh Jackman aficionado Debbie Hatt said it “sucked” though, so there’s your official review from News in Film. It made $2.2 million.

As of this very moment Horton Hears a Who! is the highest grossing film of 2008 with $148 million. But that is about to change this weekend with Iron Man and the start of the blockbuster summer season.

1. Baby Mama $18.3 million
2. Harold and Kumar Escape from Guantanamo Bay $14.6 million
3. The Forbidden Kingdom $11.2 million
4. Forgetting Sarah Marshall $11 million
5. Nim’s Island $4.5 million
6. Prom Night $4.4 million
7. 21 $4 million
8. 88 Minutes $3.6 million
9. Horton Hears a Who! $2.4 million
10. Deception $2.2 million