For a company whose only other major release was the original Half Life, Valve has pushed the boundaries with fresh, bold gameplay that stays true to the legendary legacy.

We know you want to play games, so we've put 18 PCI Express graphics cards under the microscope to see who really does the job the best.

It isn't an add-on, a mod or a new way of playing the world's most popular online shooter. Counter-Strike: Source is the same game that's known, loved and often responsible for gamers sitting motionless for days on end. But it's now been ported to Valve's new 3D engine, the Source engine, giving us our first glimpse of the technology that will be powering Half-Life 2.

A familiar plot – meddling with forces beyond our control – and some new weapons greet you as you once again enter the Mars UAC facility.

Where XFX rose early with the DirectX 8 tests and dropped off in the DirectX 9.0 tests, this card did the exact opposite - it jumped up five places to the middle of the pack in 3DMark05.

NVIDIA has been criticised for its oversized graphics cards, but the shoe is on the other foot this time with HIS putting a truly massive cooler on its X800 XT card.

We love hardware. As users ourselves we feel your pangs of wanting the newest, fastest rig and components. Unfortunately it's hard to justify the cost of bleeding-edge hardware at the best of times - more so with the cost of single graphics cards at times exceeding the $1000 price barrier. This is as much as some users would spend on a total system upgrade.