It's Hirani + Amir Khan circlejerk. 'Ooohh hirani so genius much wow concept great comedy such social message' 
OMG any day! I can rewatch it anyday and Paresh Raval has given his best. Had been PK been made by someone else like Anurag Basu, many would be saying that it's a rip off OMG or inspired from OMG. But it's Hirani. He can never do such thing right?
OMG - 8.5/10
PK - 5.5/10
