I dont like the Google and all other apps I have with my phone. I need a OS for my phone that I can surf the net, make calls, use a kind of OpenOffice app, have a contact list, etc. Thank you.
Yes you can install Ubuntu on your galaxy S III. Here is a post that someone has already asked on the subject. link here
The information pertaining to your device are available on the page https://wiki.ubuntu.com/Touch/Devices/i9300 Remember that Ubuntu Touch is still under development and we still have much work to do. It is possible to find problems or the desired software is not yet available for installation or download