I like the lines for football, it helps me keep track of what's going on better. I don't like how NBC doesn't use a blue line for the line of scrimmage. Being Canadian is probably why I like the lines in football better whereas Americans don't like them sometimes. I have a harder time following football.
On the flip-side; I can't remember hockey ever having lines but maybe that's because I've only ever watched Canadian broadcasts and let's be honest; Canadians can follow hockey better than most Americans. If there are lines in American broadcasts it's just part of the NHL trying to Americanize the game, which is fine but will never work.
01/18 & 01/19 -- Godspeed You! Black Emperor and Neurosis (in Montreal)
02/08 -- Dark Tranquility
04/11 -- Black Sabbath