
I'm pretty sure most ladies will agree with Hugh Jackman being sexy. Well check the next pic.
It has been known for quite sometime that men, on average, are hairier than women. In fact, throughout history, hair in many instances, especially in Europe, was a sign of manliness,maturity, and wisdom...and, at times, barbarianism (as in the modern definition suggesting that one is uncivilized, not simply bearded). Now it would be false to suggest that hairiness has always been in fashion, because indeed such has not been the case. Take, for instance, Russia under the reign of Peter the Great who, in the late 1600's, decreed that all men in Russia were to shave their beards. In fact, so strict was Peter with his decree that it has been stated that he personally cut nobles' beards. Of course this reasoning had a lot to do with losing wars to the West, concepts of what it meant to be "progressive" and "civilized", etc., but it is telling that it took the decree of the tzar to get men to shave their beards.

Yes, that's right, he's got a bear cub clinging to his chest, and it ain't letting go.
Fast-forward to 21st Century, and not only are men shaving their faces regularly, but, more to the point, they are also shaving other parts of their body. Chief among these areas being shaven is the chest.
Now in some populations men naturally have little to no body hair (Ex. - Many East Asian populations, many Sub-Saharan African populations, and many Native American populations), but among populations that do, specifically Western and Northern Europeans, there is an increasing trend, at least in the States and Canada, of males having baby smooth abs and chests completely void of hair. Now I am not personally against this trend, and, admittedly, I am among the number of men that do like not feeling like I'm walking around with a bear cub strapped to my chest. However, I also realized that this mindset may actually be culturally induced and I'm just following the trend in order to fit into the social and cultural norms of the society in which I live.
So the question then becomes, why do hairy men shave their chest and other parts of their bodies? Is it simply because of the society and cultural values of the nation/state in which they live? Is it due to preferences of their partner or partners? Is it simply because men now feel more free to present themselves how they wish in a society that, while still maintaining some strict gender/sex-binary stereotypes, has loosened its hold somewhat on how people are allowed to express themselves? Or could it simply be that having a metaphorical bear skin rug on your body gets a little old after awhile?
This also extends to facial hair. I've noticed that very few men, at least in professional settings, tend to grow full beards or sport stubble lined faces. I, myself, have sported both and noticed that there appears to be a presumption among many that you are either unclean, lazy, or simply look unprofessional. Now of course this could just be me, and my face might not be suited for more than a goatee. I don't know, and any opinions or experiences would definitely help to clarify what the chief cause may be concerning why most men regularly shave their faces.

The preferred look?
Now I leave you with a set of statistics gleaned from everyone's favorite and trust worthy information source Wikipedia!
There have been occasional studies documenting patterns of chest hair in men and occurrence of these patterns. A study of 1100 men aged 17 to 71 defined and documented ten patterns of chest hair in Caucasoid men. In this study 6 percent of the men were found to have no chest hair. The largest group, 56 percent, displayed pattern four as shown in the accompanying figure. The remaining 38 percent of the men displayed a lesser quantity of chest hair. Seven percent displayed pattern one, 13 percent displayed pattern two and 18 percent displayed various other patterns.[citation needed]
The same study documented the chest hair patterns of 60 African-American men aged 20-40. For these men 22 percent were found to have no chest hair. The largest group, 37 percent displayed pattern four and the remaining 41 percent had a lesser quantity of chest hair. Eight percent displayed pattern one, 12 percent pattern two and 11 percent displayed various other patterns.[1][2]
http://en.wikipedia.org/wiki/Chest_hair