Well it's really hard to say. Us, humans have really pushed ourselves to the limit.If I had to choose the top five it would be these:
The Car. Nearly everyone in the US has a car. Look outside, you can probably spot a couple cars. They have changed transportation forever and will continue to. I can't imagine life without a car.
The Cellphone. If it weren't for the cellphone we'd still be living under rocks. Cellphones have changed communication in ways we cannot grasp. Calling, text messaging, surfing the web, sending e-mail, and with the new iPhone you can now use millions of apps.
The Internet. Do I even have to explain this?
Computers. Computers are my favorite thing. I have 3 of them in my house. These machines allow you to surf the web, browse photos, watch movies, send e-mail, do hardcore gaming, and much more.
The Television. How many of us are glued to the couch, with our eyes glued to the TV screen? Everyone! The television has been our number 1 source for news, sports, comedy, cartoon, and LOST.
These are the top 5 in my opinion.