The "Fightin'" Irish is probably the most offensive of them all (the only thing that would make it worse is the "Drunken, Fightin'" Irish) and they seem to accept it just fine. In fact, rumor has it that a few Irishmen (is that PC? I know "Chinaman" is.) founded the school. But that's probably just an urban legend.
Oops, I just found out from an Englishman that Chinaman is definitely not PC. I should tell my fellow Amishmen.
East High School in Rochester, New York, is the Orientals. East Orientals.
Actually, "Fightin' Irish" was first used as an insult by, I think, Northwestern fans (or Michigan). When Rockne was the head coach, Notre Dame was known as The Ramblers. During one away game, opposing fans accused the ND players of "fighting like a bunch of Irishmen." Remember that it was probably just 30 years since "No Dogs or Irish Allowed" signs were removed from respectable establishments. But the best way to get back at your detractors is to take their insults and make them a point of pride.
Trueswine (Proud to be Fightin' Irish, '86)
Go Irish, Beat Panthers!