I've only ever seen applause at a cinema three times in the UK: 1) Star Wars (on the opening night of the 1997 rerelease at the Odeon Leicester Square), 2) Raiders of the Lost Ark (the Arab swordsman scene - this was part of a double bill I saw with the then newly released Indiana Jones and the Temple of Doom), and 3) Back to the Future (the bit when Biff crashes into the manure).