Well Dystopia is this amazing Half Life mod, totally 100% utterly and totally wicked. I think you get the idea, this has got to be my favourite mod by far, it is practically the only FPS I play now! I'll let their explanation explain what it is:

Dystopia is a Half-Life 2 modifcation which places the player into tense combat situations in a high tech world spanned by computer networks. As either Punks or Corp Mercenaries the player will fight through the physical world to gain access, via jack-in terminals, to cyberspace. Cyberspace is a three dimensional representation of the world's network. Inside cyberspace players will launch programs to hack into systems linked to the physical world, fight off enemy hackers or defend critical systems. Gameplay progresses through inter-linked physical and cyberspace objectives, some are completed in either the physical world or cyberspace, others only by a well timed combination of the two.

The player will be immersed in action packed battles, whether as a heavily augmented combat mercenary armed to the teeth with the latest in firepower and implants, or a twitch reflex cyberdecker racing to infiltrate a cyberspace node. Only through skillful use of the high tech arsenal we're making available and intelligent team play will players truly jack-in and kick ass. 

And I might add that while it may sound complicated (and it is, this is a game that requires real skill and thought to play) it is amazing. The maps are all brilliantly designed, the mods are responsive to the community, the community is great with lots of cool people. It's all just great.

Get it, get it now from here:

http://www.dystopia-game.com/