Like clockwork, Consumer Reports issues its U.S. carrier rankings ahead of the holidays each year. And like clockwork, AT&T (T) finds itself at the back of the pack. The non-profit consumer buying guide on Thursday issued its rankings for 2012 and lo and behold, AT&T again finds itself at the bottom of Consumer Reports’ overall list. The nation’s No.2 carrier did have the best-ranked 4G LTE network despite Verizon’s (VZ) coverage lead, however. Verizon was the highest-rated U.S. carrier in Consumer Reports’ 2012 rankings.