This is a free product, which in itself is impressive when you consider what you are being offered. In addition to a customizable ticketing system, you are given an inventory system, and a newly added network monitoring function which so far has been nothing short of impressive (Until now I have been using PRTG Monitor, which in itself is a wonderful tool, but not free.) The initial setup is very easy, and and Spiceworks as a service has very low hardware requirements, meaning you can run it on an older laptop fairly well.
The reporting function is a massive lifesaver, as it can help you generate a flexible list of everything from tickets (very flexible in what you want displayed, and how you want it sorted,) to your IT inventory (sorted by office location, purchase date, etc.) The ability to send these reports to our company's upper management to show hours spent on particular projects per month, or what assets need to be replaced due to original purchase date, is a very big plus.
The community portal itself is full of helpful people who are always willing to share their knowledge. On multiple occasions where I had to find a solution to a technical problem, I found people who were quickly able to pull more details from each instance, and provide a brief list of solutions in a fairly short amount of time. When you are backed against a wall, this can be a massive lifesaver.
Plugin compatibility. Some older plugins may no longer work well with newer version of the software, as well as some of the newest plugins requiring the latest update, but these are just minor nitpicks.