WMA link
TakeSmallestBy
For details on how to use the ExcludedForms option, see TakeLargest[].
TakeSmallestBy[{{1, -1}, {10, 100}, {23, 7, 8}, {5, 1}}, Total, 2]
TakeSmallestBy[{"abc", "ab", "x"}, StringLength, 1]