Four Weddings - Brilliant in that it was the first of the three, no-one really knew Hugh Grant before, so his portrayal seemed fresh. It's only the casting of Andie McDowell that doesn't work.
Notting Hill - Probably my least favourite of the three, but the scene where Hugh Grant wears his diving mask to the cinema cracks me up every time!
Love Actually - Could have done with one or two sub-plots being edited out, but overall it's my favourite. Makes you laugh one moment, then cry the next. Superb.