Being a... ahem...more 'mature' woman, I fell in love with Last Chance Harvey.' Dustin Hoffman plays a lovely gentle soul who finds love later in life with Emma Thompson. It's cute and awkward and realistic.
It's hard to pick just one. I think for me it's maybe a toss up between Crazy Stupid Love (with Ryan Gosling and Emma Stone, mainly for THAT SCENE) an the Aussie flick Love and Other Catastrophes (Radha Mitchell, Frances O'Connor and a bunch of other talented people). I tend to prefer a bit of comedy in my romance. Oh, and there's One for the Money by Janet Evanovitch which has a blend of action and comedy.