I am a happy user of TransIP STACK. They offer a 1TB of disk space per user (on the free plan) and use a modified version of OwnCloud. And best of all: hosted in the the Netherlands, so say goodbye to the NSA and say hello the AIVD (dutch secret service), just kidding haha.
Thanks to FreeVPS and Hostigation for my VPS 18!
Also a big thanks to NoUptime.host for their great FREE VPS!
I'm a Dropbox user since the beginning and I installed it to my relatives PCs and mobile devices too so file sharing is super easy.
I've tried dozes or even more free file sharing cloud services and I have to say that there is no better not Dropbox.
Here is why: It's always working, there are no server down times; it has super fast servers; my VPS connection speed or my home internet connection is the limit factor; it has a super, small and opensource client for all popular operating system (even for Linux CLI too) with a very easy to use interface; you can refer your friends and easily extend your storage space up to 20GB; and there are promotions every once in a while and with these you can reach 100GB for free too.
Mega is best option among all free services , it is fast , encrypted and secure enough . Free 50GB works for me.
I am personally using 4shared for hosting my files online. Currently I have 5 years old files still uploaded and never been at risk of deletion.
Free accounts gets 15 gb of free storage.