Like many people, I thought this would be like loads of romcoms I've seen lately (Bride Wars...eugh :P).
Like many people, I was utterly wrong.
OK, once you get over the first unexpected twist (i.e the reason for the proposal and who actually does it), it is actually pretty predictable, but like most people say, it's brilliantly executed, original and pacy. Sandra Bullock is great alongside her leading man Reynolds (although for me it's the Samoyed that steals the show. That tail! :))
I would definetely recommend buying (especially for a mere fiver) as you'll probably watch it again and again.
For all first time watchers - brace yourself when Sandra goes on a bike ride. Me and my other half haven't laughed so hard for ages ^^