In which film is Clint Barton a character?

In which film is Loki a character? Who played Natasha Romanoff in 'The Avengers'? Who played Bruce Banner in 'The Avengers'? Who played Clint Barton in 'The Avengers'? Who played Nick Fury in 'The Avengers'? In which film is Nick Fury a character? Who played Thanos in 'Avengers: Infinity War'? Who played Peter Quill in 'Guardians of the Galaxy'?