First things first: this is a very silly movie with a cardboard plot, hackneyed characters, and some atrocious dialog. BUT - nobody goes to see a movie like this for its iconic "film" moments. You go because it looks utterly ridiculous and you're in the mood for just that sort of fluff. On that basis, the movie delivers a lot of entertainment - many out-loud laughs and a variety of entertaining songs.
Toni Collette's talent reservoir seems bottomless - she can act, sing AND dance. Nia Vardalos also sings sufficiently well, and her easy, comic manner nicely leavens the somewhat hysterical character played by Collette. Together, the actresses are genuinely entertaining as they work their way through the list of Broadway standards. David Duchovny, in a role that could have been painful to watch in less competent hands, instead brings an unusually light and friendly touch to the role of Vardalos's love interest (Aside: where's he been? He's cuter than he's ever been in his life - stop languishing at home with Tea and Madelaine!).
Yes, the ending is silly; pay attention - I already said the whole movie is silly. But did I laugh loudly several times? Yup. Hysterically a couple of times? Uh-huh. Did I enjoy the musical numbers? Definitely. Will I ever feel the same way about the song "Mame" again? Not hardly. Did I get my money's worth? You betcha!