One of the websites I keep coming back to in my journey towards learning better Spanish is Notes in Spanish. The great thing about this site is that it caters for so many levels, and at the same time keeps the Spanish real. Their aim is to teach Spanish as it is spoken by real people in Spain. There is a wealth of free material on the site - podcasts, videos, blogs, free reports and useful forum. I particularly recommend the podcasts which come in three levels and which are great for listening to in the car.
The site is run by Ben and Marina who also narrate the podcasts, write the worksheets and make the videos. As you listen to the podcasts you start to feel as if you have known them for years. Ben is English but moved to Madrid several years ago where he met and eventually married Marina. This means we get to hear Marina's native Madrid accent as well as Ben's perspective on learning the language.
As well as the free material on the site there is also lots more available to buy and download in the shop section. If you sign up for the newsletter then they will occasionally email you with special offers.
It is hard to come up with any downsides to this site. The Spanish is generally that from Spain, so those wanting to learn Latin American Spanish need to bear in mind that some things may be a little different. Also, the starting point is a little beyond complete beginner, so it is best to learn a little of the very basics elsewhere before tackling the beginner material on this site. Overall this is a fantastic Spanish resource, with lots of material for free and even more to buy at a reasonable price.