I think Discussions or Brainstorming, Role Plays, Interviews, Debates, Information Gap, etc are popular activities. The activity I like is 

 discussion.

- Level of student: grade 10

- Time: 20 minutes

- Rules: T divides class into group of four or five. After that, T gives  a topic & instructions to students such as "Collecting stamps". T asks ss to discuss together and then they may note down some main ideas. Each group will choose a student to talk about the topic in front of the class. Ask other groups give comments and then T gets  feedback.