Defense of the Ancients may have gotten its start as a humble WarCraft III mod, but League of Legends is where the peculiar mix of competitive roleplaying and tower defense arrived at maturity.
The appeal is in the huge array of selectable characters, all of which bring something different to the table. And being a "freemium" title with relatively spec requirements, it is open to pretty much anyone with a PC. Watch out though--League of Legends has a highly competitive community, and you will almost certainly be in for some hazing.
The best solution? Bring a friend and explore this highly popular game together.
You can now play Plants vs. Zombies on almost every gaming device, but it all started on PC. The desktop tower defense action tasks you with guarding your house from an encroaching zombie horde through the strategic use of adorable plants. PC games have access to the extra multiplayer modes that were introduced in the other versions, and the keyboard-and-mouse interface is still the best way to manage your foliage army (though the iPad version isn't bad either).
Ultimately, PvZ stands out from other tower defense titles because of it's charming style and catchy soundtrack. It's easy for a company to throw together a game like this with the same gameplay; it's hard for them to do it this skillfully.
7 | Rift
World of WarCraft has been the proverbial king of the hill for many years now, but that didn't stop Trion from going out and creating their own vision of what an MMORPG should be. Their "Dynamic Fantasy MMORPG" brings the world to life with the eponymous rifts from which monsters of all shapes and sizes are constantly menacing players and towns.
It's the first step toward creating a world that actually feels alive, rather than a simple series of quest hubs. Add in the ability to switch between multiple character builds with easy, and you have an MMORPG has quickly become a favorite among the genre's hardcore fans.