I'd go with the final scene in A New Hope when Hans returns to save Luke from Vader. As a young kid watching this the first time - nothing can top it.
In Happy Gilmore - when Happy thinks of a 'happy place' and Shooter comes into the dream and kisses his woman and grandmother - and of course there is the little guy - that always cracks me up.
Snake on a Plane - the part where the big guy doesn't want the Flight Attendant to suck the poison from his butt.