I suppose, it really depends on the age and level.
if it is junior students, possibly they would like to have some fun games in the class.
if it is adults learners, they probably enjoy role playing games, just like what Kiyama said.
or enjoy listening to some different culture and customs from different countries.
in addition, one of the best ways is to do thou is to get an English book.
some books like, "New concept English", "English in Mind", etc.
those books are great and very popular in my city, many students learn it with their teachers.
coz each book has different levels so students can make great progress after a period of time.