Grabing hashtagged word from a string using regex

How good do you want this pattern to be? In theory just:

"(?<=#)\w+"

would do it.

Edit, for more answer completeness:

string text = "This is a string that #contains a hashtag!";
var regex = new Regex(@"(?<=#)\w+");
var matches = regex.Matches(text);

foreach(Match m in matches) {
    Console.WriteLine(m.Value);
}

string input = "this is a string that #contains a hashtag!";
var tags = Regex.Matches(input, @"#(\w+)").Cast<Match>()
                .Select(m => m.Groups[1].Value)
                .ToList();