Ah, abs. Those wondrous things that, because of the recent release of Magic Mike, we are reminded to give thanks for this week (a.k.a. Gratuitous Male Objectification Week). Today, we'd like to acknowledge the historical importance of some of the forefathers of shirtlessness — the guys who paved the way for today's Channing Tatums and Matthew McConaugheys. Would Baby really have had the time of her life if Patrick Swayze had been wearing a shirt during all those dance lessons? Would Marky Mark have been able to produce such good vibrations without visible pecs? And where would Arnold Schwarzenegger be today if an image of hulking muscles didn't come to mind every time someone said, "Hasta la vista, baby"? Click through the slideshow to see all these half-naked dudes and more.