Rhinoceros Beetle

You have a male. The female has no horns. You can see them together in my ID link. Both ID suggestions are correctly called Rhinocerus beetles. However, Orycetes has a shorter thoracic horn and Xylotrupes has a very long (usually) thoracic horn. Males use their horns in battle to dislodge other males from their branch and win mating rights with a show of superior strength (or size). Sometimes your spotting is mislabelled Orycetes and you can find several other misnomers online, eg. http://www.panoramio.com/photo/19908294 but this is the real one http://commons.wikimedia.org/wiki/File:Oryctes_species,_rhinoceros_beetle_male,_Scarabaeidae_EOS_063.jpg

male or female

You're welcome! That's a cool beetle!