No options required
Regex:
\w+|"[\w\s]*"
C#:
Regex regex = new Regex(@"\w+|""[\w\s]*""");
Or if you need to exclude ” characters:
Regex
.Matches(input, @"(?<match>\w+)|\""(?<match>[\w\s]*)""")
.Cast<Match>()
.Select(m => m.Groups["match"].Value)
.ToList()
.ForEach(s => Console.WriteLine(s));