Best Free Sites for Online Storage? Advice Welcome!

Ok, so I have a good computer, but do worry, because I am a music addict... and have a few too many photos stored too, I'll admit! I have to wonder how much faster my computer would be if I weren't storing it all on my harddrive. I've been doing a bit of searching tonight, but several of the sites delete your accounts if you don't use them for a certain amount of days, etc.

Which sites have you had success with? Do they offer enough space for a LOT of songs? Do they delete your account if you don't log in often enough? Are their free plans decent, or is it worth it to just go ahead and pay for the upgraded plans?

Would love to hear your opinions and recommendations!

Thanks all, and hope you all have a very Merry Christmas, or a happy time, no matter what you do, or don't, celebrate!