This UK-based site gives reviews of different providers and also lists the costs and features of each service. The reviews emphasize paid services as these offer more storage space and are meant for regular/daily users who need to store lots of files. So if you are in the high megabytes or even pushing a terabyte when it comes to the amount of space you need, this site is going to be useful for you in looking at affordable paid options for cloud storage.
I found the site interesting as the only provider on the top ten list that I was personally familiar with was Dropbox, so I appreciated learning about other options. Six of the top ten currently listed offer unlimited storage, which is pretty cool if you ask me! And the reviews are very thorough in explaining exactly how each site works in terms of upload, storage, dashboard, etc, and what you're getting for your money.
If you are like me and have smaller needs in terms of cloud storage, you might like the article that Cloud Storage Top 10 has posted about free cloud storage options.