Recommendation? If you like this playstyle, there are not many games that offer it, and Darkfall has been around long enough to work out most of the major bugs and balance issues. Other than EVE Online, Darkfall is probably the best-supported and populated PVP sandbox game out there. An important caveat to note is that Aventurine is working on Darkfall 2, which is likely to replace Darkfall at some point in the future. This can make investing a lot of time in the existing game risky, as Aventurine has been open that the bulk of their corporate resources are focused on the sequel game. Very recently, Aventurine dropped the requirement to purchase the game itself, allowing you to pay just the subscription fee.

The 14-day trial is long enough to allow you to judge Darkfall Online. After that, there's a $15 per month fee (or $40 for a three-month subscription), with no cash shop, microtransactions, or free-to-play options.

Note: The Download button takes you to the vendor's site, where you can download the latest version of the software.