如何将列表保存到文本文件？

At the moment I have this and it saves (System.Collections.Generic.List'1[System.String]) but I want it to save the text in the string.

private void btnSave_Click(object sender, EventArgs e)
{
    TextWriter tw = new StreamWriter(lblName.Text + ".txt");
    tw.WriteLine(save);
    tw.Close();
}