Some thoughts on a few of your choices:

Crazy, Stupid, Love - I rather like this one. Quite underrated.

Leap Year - The only film on this film I actively dislike (Mark Kermode was right to dismiss it as "Leapy Ear").

It Happened One Night and When Harry Met Sally - Two of my all-time favourites, and also on my list of favourite romantic comedies (see below link, if you're interested). :)

https://fanfare.pub/my-twelve-favourite-romantic-comedies-8ca63366a198