Exibir o valor do rótulo suspenso personalizado com LINQ (Razor)

//In your .cshtml file

@{
var newSource = YourModel.SomeCollection.Select(m => new SelectListItem
{
Value = m.YourValueField.ToString(),
Text = string.Format("Custom Text {0}: {1} {2}", m.FirstTextField, m.SecondTextField, m.ThirdTextField)
});
SelectList finalSource = new SelectList(newSource, "Value ", "Text");
}

@Html.DropDownList("ControlName", finalSource)