std::cin input with spaces?

It doesn't "fail"; it just stops reading. It sees a lexical token as a "string".

Use std::getline:

int main()
{
   std::string name, title;

   std::cout << "Enter your name: ";
   std::getline(std::cin, name);

   std::cout << "Enter your favourite movie: ";
   std::getline(std::cin, title);

   std::cout << name << "'s favourite movie is " << title;
}

Note that this is not the same as std::istream::getline, which works with C-style char buffers rather than std::strings.

Update

Your edited question bears little resemblance to the original.

You were trying to getline into an int, not a string or character buffer. The formatting operations of streams only work with operator<< and operator>>. Either use one of them (and tweak accordingly for multi-word input), or use getline and lexically convert to int after-the-fact.

You have to use cin.getline():

char input[100];
cin.getline(input,sizeof(input));

The Standard Library provides an input function called ws, which consumes whitespace from an input stream. You can use it like this:

std::string s;
std::getline(std::cin >> std::ws, s);