f(MostLeaky).
MostLeaky = fun(N) ->
    lists:sublist(
     lists:usort(
         fun({K1,V1},{K2,V2}) -> {V1,K1} =< {V2,K2} end,
         [try
              {_,Pre} = erlang:process_info(Pid, binary),
              erlang:garbage_collect(Pid),
              {_,Post} = erlang:process_info(Pid, binary),
              {Pid, length(Post)-length(Pre)}
          catch
              _:_ -> {Pid, 0}
          end || Pid <- processes()]),
     N)
end.
%% Pairs = MostLeaky(25).