but do hiking most, as it doesn't need any equipment hehe

其实ｃａｍｐｉｎｇ对我来说就是ｈｉｋｉｎｇ或ｂｉｋｉｎｇ的附属。要是走到哪儿要睡觉的时候那儿放着一个不要钱的旅馆，我肯定会弃ｃａｍｐ而去旅馆的。不过我的朋友就跟我说他在青年旅馆的后院ｃａｍｐｉｎｇ过，说是一路ｃａｍｐｉｎｇ到那里习惯了睡觉时有只属于自己一个人的空间

wrong, at least u have to have a good shoes and a backpack
pants? socks? rain gear? water container?....

indoor camping?
still have to pay for campground in some park

backpacking =hiking + camping

It is not always the case. You can drive to a camping site to camp and only do daily hiking, which you only carry water and some snack during the hike. Backpacking to me it is more like a more than one day trip to the more remote nature where you have to carry everything you need with you. It needs more energy, strength and passion. I can do camping and hiking, but I know I am not ready for any backpacking trip.

en, yeah, i think i will enjoy the privacy in camping too, but not at the time that bear or coyote is around, hoho

i voted for hiking
although i probably have evenly distributed interest for all the activities you mentioned ;-)