Unit test with bulky assert section. The unit test uses Autofixture, FakeItEasy and FluentAssertions.

UnitTestWithBulkyArrangeSection.cs

[Fact]
public void GetHighestRatedMovies_RepositoryContainsMoviesWithRatings_ReturnsMoviesOrderedByDescendingRating()
{
    // Arrange
    var fixture = new Fixture();
    var movieCollection = fixture.CreateMany<Movie>(20).ToList();
    var fakeMovieRepository = A.Fake<IMovieRepository>();
    A.CallTo(() => fakeMovieRepository.GetAll()).Returns(movieCollection);
    IMovieService movieService = new MovieService(fakeMovieRepository, null, null);
    MovieServiceRequest request = new MovieServiceRequest { NumberOfMoviesToReturn = 5 };

    // Act
    IList<Movie> movies = movieService.GetHighestRatedMovies(request);

    // Assert
    movies.Should().BeInDescendingOrder(movie => movie.Rating);
}