Well, after a couple hours reading stuff over here, trying unsuccessfully all the solutions, also found this article that i thought it would save my life... nothing.
ViewBag.yearDropDown = new SelectList(years, "Value", "Text", years.Where(x => x.Selected).FirstOrDefault());
Last parameter here is SelectListItem, but it must be selected value (string in your example)
SelectListItem
value
SelectList Constructor (IEnumerable, String, String, Object)