Those Hobbits like a good dance. Dancing games to some of the more jiggy soundtracks with Hobbity names could go down well.
You know the game where you draw a line down the centre of the hall, put a load of balloons on either side and the aim is to have no balloons on your side via chucking them all over the line in to the other team's area? Maybe they could all be yellow/grey/white/gold/silver balloons. Maybe the Hobbits stole Smaug's treasure and need to get rid of it before it finds them?
How about a serious of riddles care of Gollum?
Pin the beard on the dwarf?
Something a bit like What's The Time Mr Wolf but with an orc, and in the dark (as dark as you can make it in the middle of the day) with everyone holding glowing blue swords (glo sticks from their party bags)?