MediaFire has launched their cloud storage app for Android today, offering new users 50 GB of storage for free. Files can be easily shared via e-mail, social networks, SMS, and just about any other avenue you could need. There are a whole bunch of subscription tiers if you need to host more files, or need more flexibility with your hosting.
MediaFire had to dodge a few accusations once it got lumped in with MegaUpload as a focal point of illegal file sharing, but they've done a good job clearing out any offending content. Now MediaFire is right up there with Box.net and has a web interface that's easily as nice as DropBox's. Though the Android app is fairly bare-bones for now (the lack of uploading from the system Share menu is a little tough to swallow), the website has a great photo viewing interface, smart keyboard shortcuts, and simple drag-and-drop functionality. If nothing else, the mobile app will be a fine spot to access files that you've been uploading from the desktop.
Which cloud storage service do you use the most? Is Google Drive good enough, or do third-party options offer you something else?