I haven't seen Bride Wars, but I must say that 27 Dresses is HYSTERICAL.
I love it so much. There's parts where you really HATE characters, and when you LOOOVE characters. That's perfect. When a movie can really get to you like that it proves it's a good movie. So I really must suggest 27 Dresses hands down.
*I never liked Kate Hudson as an actress.. She's so boring and ..blech.
BUT Katherine Heigl is pure enjoyment to watch. So is James Marsden
Bride Wars. Its super funny and it would be extra great to watch with some of your best friends! I would defiantly watch Bride Wars. I watched it at a sleepover with one of my Best Friends, and That makes it even funnier...