in my opinion 
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.

ex : I would like ask you some question about your hobbies 

       What is your hobbies ? My hobies is reaading book / I like reading book

      When do you often read book ? I often read book when I have free time....

      What kind of book do you often read ? why ? I often read comic book  because  it is easy to read  

......

+After that  sts report in front of the class

+Teacher give feetback