Baby Mama (2008)
Chosen by me from my stack of unwatched DVDs
This plays the usual game of Rom Com shuffle, where a successful single woman is not seen as whole until she has a family (though not nearly as horrid as some recent examples like The Ugly Truth) this at least puts the females front and centre (Greg Kinnear is a bland nothing) and is a lightweight fancy.
Nothing here is very funny but it's not grossly offensive either, trading on some lazy tropes ('they're the original odd couple!') but bolstered by Poehler and Fey's easy chemistry and good comic timing.