Jottacloud is aloso very cool, it gives you plenty of storage which is expandable to 100gb for free :-) and it supports windows and Android! If you sign up with a referral link and install the android app, you will get 12gb!
jottacloud (new cloud storage and sync), start with 10gb, +5gb per referral, upto 100gb all for free; my referral: jottacloud
dropbox referral : dropbox
Copy (start with 15Gb+ 5Gb) free! https://copy.com?r=qTMfqi