List 'Except' comparison - ignore case

Here's what worked:

IEnumerable<string> differenceQuery = inputTable.Except(strArrList,
                                                        StringComparer.OrdinalIgnoreCase);

Used StringComparer instead of StringComparison.

Try this :)

List<string> except = list1.Except(list2, StringComparer.OrdinalIgnoreCase).ToList();

Worked for me!