I cannot stress how great the Harry Dresden series is. The secret here, like most fantasy, is you absolutely have to read past the first book. It is good, but the series itself is great. Harry Dresden is the country's only opening practicing Wizard. The Dresden Files has an amazing ensemble cast, with a hard-boiled private detective in the lead. Who just happens to be a wizard. There are also werewolves, vampires, fairies, clairvoyants, ghosts, necromancers, demons, and a host of other supernatural beings. I often bill it as Harry Potter for grownups. Although it is a little more based in our world typically than a fantasy world, I think, the comparison still holds true.
Jim Butcher has written 13 Dresden books, and a short story collection, and he's not done yet. He will release another this year, and for many years to come. So if you run out, he'll make more.
We typically try to keep most of the series in at any given time new, because although it began over 10 years ago, I have only seen one copy of the first book used. People love it and don't give it up. You can't have my copy.
Also an amazing series, The Dark Tower, by Stephen King. This one starts with The Gunslinger. This is another series that once you read the first book, you absolutely immediately have to pick up the second and move on. You will not regret it. The Dark Tower is epic fantasy, and doesn't really hit it's stride until the second book when King has introduced us to most of the main characters. It is about Roland Deschain's quest for the Dark Tower, but more than that it is about the journey. This we do have it available used, but make sure you pick up the first two, and not just the first one. It would be a great tragedy if you read the first and then stopped.
Although the series is technically finished, King has written a novel that bridges the gap between the 4th and 5th books that will be released in April. There is also a two volume concordance and several graphic novels.
I'll leave you with these two for now, as between the two series they amount to over 21 books. That should keep you busy. And if fantasy is not your cup of tea, there is always something we can recommend for you. We take recommendations very seriously, so give us a shot. Are there any great books you have read lately that you would like to tell us about?