Thanks for all the great suggestions for romantic comedies! Since a few of your asked, here are any results that brought up more than one suggestion:
2005 and newer:
*The Holiday - most suggested movie! I've seen it once and agree it's one to own.
*Because I Said So - I was told this is a great mother/daughter movie.
*The Devil Wears Prada
*The Family Stone - it was mentioned to me that this movie might be iffy in sections
*In Her Shoes - I saw it and liked it, although it has a few scenes that are iffy
*Serendipity - I already own this movie and watch it all the time!
*The Cutting Edge
*Eternal Sunshine of the Spotless Mind
I'm excited to see what I end up with!