What are the best 3rd party DRM solutions available from a user experience, development integration, and security perspective?
There is no such thing as good DRM. Consider it from the computer owner's perspective: DRM is a program whose function is to override the owner's ultimate control of the system and allow some other programmer somewhere else to dictate what he can and cannot do with the computer, which is his personal property.
In any other context, this would be considered computer hacking, which is a serious crime. The only reason people can get away with using DRM today is because the DMCA explicitly turns the entire legal issue inside out. (It's now legal to hack anyone's computer pretty much however you want to as long as they have your copyrighted material on it, and the owner is the one guilty of a computer crime if they try to assert their natural right to control over their own property.)
When programmers say they want DRM, what they really mean is that they want to protect against lost sales. This is both futile and counterproductive. Futile because in the age of the Internet, all it takes is for one person, anywhere, to produce a working crack and upload it somewhere, and your DRM is broken everywhere. Counterproductive because DRM causes inconveniences for the user which lowers their perception of its quality and thus their incentive to buy it. Just look at Spore, which was a mediocre game, but nowhere near as horrible as its reputation would have you believe. It got crushed by backlash against its DRM, not by the game itself being bad. On the flip side, look at Sins of a Solar Empire, the best-selling game of its year, released 100% DRM-free. Consumers saw the lack of DRM as a positive feature that increased the perception of quality significantly.
There is only one way to get people to pay money for your game, and it's not by hacking their computer. It's by releasing a product whose perceived value is greater than the price you're asking for it. Don't waste effort even thinking about DRM; work on making a game people will want to play.
For a PC title, Steam is really the only one that should be considered these days. Safedisc and SecuROM install terrible things onto the user's computer and cannot be uninstalled.
From a security perspective, 3rd party DRM is never good, as it allows hackers to apply knowledge gleamed from other products using the same middleware.
Middleware and copy-protection are pretty much mutually exclusive, getting a custom solution will at least defer the process a bit allowing some sales before the game is hacked.
Although I assume you're asking for PC games, I would like to add that Google provides their own license system for Android developers.