Heres a first post to get things going.....
I love these following romantic comedies:
Can anyone recommend similar movies I might like??
Here's a few.
Forgetting Sarah Marshall (2008)
Something New (2006)
27 Dresses (2008)
Obviously genre specific recommendations are a bit different than recommendations based on liking movies a,b and c.Especially one like Romantic Comedies, never know where or what someones threshold is.
Monster In Law
The Wedding Planner
While You Were Sleeping
Never Been Kissed
I have seen all of those not no res. though! What is it abou?
Accomplished single chef finds herself guardian of dead sisters young child. similar to Mostly Martha.
Not all of these may be similar to what you listed, but
PS I love you,
The Family Stone
The Phildelphia Story
You've Got Mail
Same Time, Next Year
The Goodbye Girl
In Her Shoes