I think some of them were in an earlier generation, when local broadcasts weren't as numerous and there were only a few national networks broadcasting sports. Gowdy, Garagiola, Summerall, Madden, Enberg, Lindsey Nelson, and others were liked by almost everyone.
Most announcers don't bother me. The ones who try to make themselves the focus are the ones that annoy me--Howard Cosell, John Sterling, Romo to an extent.