Tresorit! safer than dropbox and has a handy UI. I am currently testing their Android app which has a new UI and I even more like that one. (and I also got 50Gb as an early bird user)

well said, they don't provide any encryption - and I have not found any public cloud services that could solve the browser encryption issue. If you are willing to experiment with public services, my first bet would be tresorit (however, they have limitations in compatibility until august, when upgrades are coming). I also tried wuala and boxcryptor, but they just did not work for me.