I'd say the best simple competitive game I've played is speed reading. I set up 10 sentences (the key phrases from the lesson and variations) in a horseshoe pattern at the back of the class. Split the class in two and line them up at each end of the horseshoe. Each team starts reading at one end of the horseshoe. Whenever they meet, they RPS and the winner keeps moving along the horseshoe. The loser goes to the back of their team's line and then the player at the start of the line goes. This game is AWESOME for low level students because all they're doing is reading the sentence. My co-teachers and I follow the students to make sure they're actually saying the sentences. Once a student reaches the end of the horseshoe, that team gets a point. I usually play for about 15 minutes and sometimes rounds can go a really long time if you have a fairly mixed level class.
My reflections on this game are that boys seem to enjoy this more than the girls, but it's still a great way to practice reading and speaking and has competition involved.
Another really great game I've played that works with a large classroom is called soldiers vs. ninjas. There is a PPT on here somewhere, but now that we have to pay, I'll just explain how to play. I choose 10 students - usually higher level students or students who have performed well in class that day. These are the soldiers. There are 3 levels and one "King". The "King" is the best student that day. The first level has 4 soldiers, second level has 3 soldiers, and the third level has 2 soldiers. Have the soldiers stand in a row in their levels with the king behind level 3. Then the ninjas line up in front of level 4. Let 4 ninjas go at a time - the soldiers ask the key phrase question and the ninjas answer the question. When they are done, they RPS. If the ninja wins, he goes to the next level soldier and if he loses, he goes to "jail." Once a ninja reaches the king, have a "King battle." I like to make a big deal out of the King battle and stop everyone to watch. This game isn't necessarily competitive, but every time I've played, my students get really into it and want to be the king each time.
They basically love any game where they can play RPS.
