There are many speaking activities, such as: Discussions or Role Plays, Interviews, Debates, Information Gap, etc. The activity I often use is Information Gap

In this activity, I  divide our class many small groups .  I will create two different versions of a dialogue and hand out version A to Student A and version B to Student B. The idea behind this is all the B section sentences that are missing on version A appear on version B; and vice versa.