Massively Multiplayer by P. Aaron Potter is an amazing book and a great example of the eBook revolution and the kind of quality that can come from it. I picked it up via a Humble Bundle and I must say, there were certainly quite a few good books in there but this one stood out.
Massively Multiplayer revolves around the game Crucible. It's the foremost online RPG system available and where schoolkid Andrew Hunter goes to relax and run away from the world. It's also the program that Wolfgang Wallace manages, overseeing all aspects of the game as the head of IT. They both get caught up when Crucible changes hands and a hacker starts targeting the game with unknown intentions.
The book itself is relatively well written with characters that are real and interesting. Andrew's a typical teenager, trying to find himself and enjoy the last parts of his childhood while Wolfgang is just a man who loves his job. So the protagonists hold up relatively well - unfortunately, where Potter falls down are his antagonists. They rarely have much depth to them and are somewhat caricatures. In a few cases, the resolution for the characters is unsatisfying as well, with the antagonists used more as plot points rather than characters.
On the other hand, the overall book itself is engaging. I read through it in one sitting because it was just that well written. With two parallel (for the most part) storylines, we have the typical 'quest' for Andrew in an online game and a mystery for Wolfgang as he searches for the hacker. At first, the stakes don't seem high but they ramp up as they book goes along.
Overall, I'm looking forward to seeing what else Potter has to write. It won't be in this universe - he wrapped it up quite nicely, but he certainly has talent and potential.