Consider this a crash course on video card naming conventions for the uninitiated. After reading this primer you should have a basic understanding of how video card models are named so that you have a better idea of what your system is capable of playing, as well as making smarter purchases on future upgrades.

Intel
Let's start with the least intuitive chip maker. You're likely to find integrated Intel video chipsets in laptops, cheap PCs, and small form factor PCs. For the most part, Intel's video chipsets are harder to qualify at a glance of the model name. There is a handy Wikipedia article which lists the order of their release and relevant feature support here: http://en.wikipedia.org/wiki/Intel_GMA . If you care about 3D gaming performance, you don't want an Intel for your graphics chipset. To squeeze some extra performance out of your Intel chipset, see tools like GMA Booster and 3d Analyze.

nVidia
nVidia has adhered to a legible naming scheme for about a decade. An nVidia model typically has a family name, model number, and suffix.

Families
The two predominant families you are likely to see are the GeForce and Quadro. GeForce is your standard consumer-grade, gaming video card. Quadro is specifically tuned to boost performance in 3D design software like AutoCAD. Quadros will play games, too, but will never outperform a similar GeForce board and some PC games have been known to have issues running on Quadros.

Model Number
nVidia model numbers have two significant parts. The first digit indicates generation, the remaining digits indicate power/strength/horsepower. For example, the GeForce 7600 is a 7-series card and has a performance value of 600 out of a possible 950. Another card, a GeForce 9400, is a 9-series card and has a performance value of 400 out of 950. Comparing the two, the 9-series card may support some newer bells and whistles, but the 7600 may perform a little better when it comes to rendering your games.

Newer generations have adopted a 3-digit naming scheme. Some current products are the GT 120 and GT 265. Same logic applies, just make sure you understand that a GT 265 will significantly outperform a GT 120.

Suffix
Ahhh, the suffix. Seems like there are new suffixes every time a new generation is released. These are hard to nail down, but they also have relevant indication of horsepower. GS sometimes means underclocked, or less powerful. GT is kind of a middle-ground. GTX typically means "performance" or "enthusiast" class products for gamers who demand the most from their systems. M is another common one; it means the card is a mobile version of another card, meaning it has a smaller power draw for battery life and sacrifices a bit of performance to achieve this.

Obsolete nVidia generations: GeForce, GeForce 2, GeForce 3, GeForce 4
Aging generations: GeForce 5, GeForce 6
Gets the job done: GeForce 7, GeForce 8
(GameTap recommended) The new hotness: GeForce 9, GT 1xx, GT 2xx

ATI
Heads up to all that CPU manufacturer AMD purchased and now controls ATI graphics cards. Hope that clears up some confusion...

Same stuff applies to ATI naming conventions. They, too, have familes, generations, model numbers, and suffixes. Replace GeForce with Radeon and Quadro with FireGL above. Same basic performance numbers and suffix info applies.

Obsolete ATI generations: Radeon 7xxx, 8xxx
Aging generations: Radeon 9xxx, X-series
Gets the job done: Radeon X1xxx-series, Radeon HD 2xxx series
(GameTap recommended) The new hotness: Radeon HD 3xxx, 4xxx series

Bottom line = If high performance in the latest 3D PC games is critical to you, look for video cards with performance numbers above 60%, i.e. a GeForce 9800 or GT 260. In ATI-land, examples include Radeon HD 3670 and Radeon HD 4850. Don't expect something like a GeForce 9250 or Radeon 3400M GS to render the latest and greatest at 30 frames per second.