The landscape of graphics cards can become confusing, but luckily we have benchmarks published in many sites that help us to assess the relative performance of each card. To help you decide which one is the optimal graphics card for your laptop, I have drawn a chart covering the most usual laptop graphics cards at the moment. The chart plots 3DMark 06 scores and data are from Notebookcheck tables: this is just an effort to make the available information more graphical and simple. If the graphics card you are interested in is not listed in the chart, it is lileky that it is in the original tables. In addition, you can find useful the laptop processor benchmark comparison, the benchmark section and the gaming laptop section.
You can also be interested on the laptop benchmarks contributed by users
Card listing: Intel GMA 950, GMA X3100, GMA 4500MHD; Nvidia GeForce 8400M GS, 9200M GS, 9300M GS, 9400M, 8600M GT (DDR2 and DDR3), 9500M GS, 9600M GT (DDR2 and DDR3), 8700M GT (single and SLI), 8800M GTX (single and SLI), 9700M GTS, 9800M GT (single and SLI) and 9800M GTX (single and SLI); ATI Mobility Radeon HD 2400, 3200, 3450, 3470, 3650, 3850 (single and CrossFire), 3870 (single and CrossFire).
Background color represents the ability of the card: red, not good for games (save older ones); yellow, good for games light on resources and HD movies; light green, good for most games; dark green, good for all games. This is an oversimplification, and depending on the game/card combination you may need to lower resolution or detail. But I think it’s a good approximation.
In case you have any questions, you can use the message boards to ask them.