object array or collection

It depends on how you will store the data. Also, I think you are describing genre for movies. There are other ways to categorize movies and I think it is worthwhile analyzing and designing what you want to do to categorize movies. There are sites such as imdb.com that should help you deciding what you want to do. You could let the individual user decide what categories they want, but I think most people would prefer to have a more standard design. Or you could do both; standard categories and individual categories.
 
Assuming you will use the same genres used by other sites, you could have a table of genres and/or other categories. So you would have at least the following tables:

• Movie
• Category
• User

I think you would need two more tables; one that lists the categories of a movie and another that lists the movies for a user.

 
You could use a SQL database for the data, instead of arrays. The .Net has extensive support of databases and database tables so most of what you would do can be done efficiently using a database and database tables.

Hi,
You need to try with custom collection class. This custom class needs to bind with specific user rofile class. It's something like below.
public class Movie
{
public string MovieName
{
get;
set;
}
public string MovieType
{
get;
set;
}
}
public class MoviesCollection : CollectionBase
{
public IList GetList
{
get
{
return List;
}
}
public void Add(Movie movie)
{
List.Add(movie);
}
}
public class UserProfile
{
public MoviesCollection UserCollectionType
{
get;
set;
}
}
public class Client
{
public void FillMovieList()
{
//User1
Movie user1Movies = null;
UserProfile user1 = new UserProfile();
user1.UserCollectionType = new MoviesCollection();
user1Movies = new Movie();
user1Movies.MovieType = "Comody";
user1Movies.MovieName = "Some Comody";
user1.UserCollectionType.Add( user1Movies);
user1Movies = new Movie();
user1Movies.MovieType = "Horror";
user1Movies.MovieName = "Some Horror";
user1.UserCollectionType.Add(user1Movies);
//User2
Movie user2Movies = null;
UserProfile user2 = new UserProfile();
user2.UserCollectionType = new MoviesCollection();
user2Movies = new Movie();
user2Movies.MovieType = "Family";
user2Movies.MovieName = "Some Family";
user2.UserCollectionType.Add(user2Movies);
user2Movies = new Movie();
user2Movies.MovieType = "War";
user2Movies.MovieName = "Some War";
user2.UserCollectionType.Add(user2Movies);
//User1 seeing his collection
foreach(Movie movie in user1.UserCollectionType.GetList)
{
Console.WriteLine(movie.MovieName);
Console.WriteLine(movie.MovieType);
}
foreach (Movie movie in user2.UserCollectionType.GetList)
{
Console.WriteLine(movie.MovieName);
Console.WriteLine(movie.MovieType);
}
//LIKE THAT EACH USER CAN ADD THEIR OWN
}