I was just wondering how I could make an informed decision on which graphics card I can get for any number of laptops. I have looked at several laptops and have narrowed down a few, but I'm not 100% sure that I would be getting a better graphics chip from one maker or another. Here are a couple of examples of what I've been looking at.

Dell e1705 Laptop
Inspiron E1705 Intel® Core™ Duo Processor T2300 (1.66GHz/667MHz FSB)
Operating System (Office software not included) Genuine Windows® XP Media Center Edition 2005
LCD Panel: 17 inch Wide Screen XGA+ Display
Memory: FREE!1GB Shared Dual Channel DDR2 SDRAM at 533MHz
Video Card: 256MB NVIDA® GeForce™ Go 7800
Hard Drive: 60GB 5400RPM SATA Hard Drive
Network Card: Integrated 10/100 Network Card and Modem
Combo/DVD+RW Drives 8x CD/DVD burner (DVD+/-RW) with double-layer DVD+R write capability
Wireless Networking Cards Dell Wireless 1390 802.11g Mini Card (54Mbps)

MSI 1036
Processor: Socket 754 AMD Mobile Athlon64 35W/ Mobile Sempron 25W/ Turion64 MT or ML
Memory: 2 memory slots expandable to 2 GB. Supports DDR 333/400 SODIMM modules
Chipset: ATI RS 480M + SB 450
Hard Drive: Supports 2.5" 9.5mm IDE HDD with Ultra ATA-100 up to 120GB
Graphics: ATI Mobility Radeon x700 w/ 256MB VRAM
Display: 17" TFT WSXGA+ (Glare Type 1680x1050) w/ 1.3MP Camera
Optical Drive(s): Dual Layer/Format DVD Burner Included
Networking: Integrated 10/100/1000 Ethernet
Modem: Integrated AV.92/56K fax/modem
PCMCIA Slots: Express Card x 1, PCMCIA 2.1 Compliant, Type II x 1
Pointing Device: Built-in touchpad with 2 click buttons
Sound: Realtek ALC 882, SoundBlaster Compatible w/ 4 speakers + subwoofer
Memory Readers: MMC/SD/MS/MS Pro/XD 5-in-1 Card Reader
WiFi: Intel Pro Wireless 2200 802.11b/g, Intel Pro Wireless 2915 802.11a/b/g Wireless LAN or MSI MS-6855 WiFi/Bluetooth combo module optional

My major question is what is the better graphics chip that I can buy? I know that the nVidia 7800 is supposed to be better, but I've on different forums that the plain jane 7800 is at lower clock speeds and doesn't perform to the true 7800 speed.
Most of my research shows that the x700 is a pretty good graphics chip and is probably more affordable than getting the 7800 chip, which Dell owns.
I've also seen some reviews on the nVidia go 6600 and was wondering if is an equivalent to the x700 or is it a little less than it?
So if someone know some information about some of these graphic chips for laptops, please let me know. I'm hoping to purchase a laptop for gaming, but only have about $1,500 to spend, so I know that limits what I can get, but I think the x700 w/256mb DDR should hopefully work for some time.
If I were to rank a few laptop graphic chips here is how I would rank them, by what I've read (not anything that I've experienced though):
(ranked from slowest to fastest)
ATI x300
ATI x600
nVidia go 6600
ATI x700
nVidia go 6800
ATI x1400
nVidia go 7800
ATI x1600
nVidia 6800 Ultra
nVidia 7800 GTX

If this seems to be fairly correct, please let me know. I don't think I'm too far off, but I've been wrong before. Thank you in advance for any comments/suggestions that you may have.

The 7800go is nearly equivelent to the 7800gtx, with only slightly lowered clocks. 5 minutes of overclocking and you will give that chip a run for its money. The 6800go and 6600go are also excellent choices, both essentially performing at 6600gt and 6800ultra specs respectively. There is no such thing as an "x1400", you probably meant x1300. This is really a matter of how much you are going to spend on gaming. If you have a high-res screen and plan to do gaming past 1280x1024, get a 6800go or 7800go or an x1600 wouldn't be a terrible choice. The best card for a budget, however, would most likely be the x700, which will hold its own but get pounded by newer high end cards in the 6xxx/7xxx series.

The x1400 gpu that I was refering to is in the newer IBM (Lenovo) laptops.

Specs of the ThinkPad T60 Being Reviewed:

Model #: 2623-D3U
Processor: Intel T2500 2.0GHz Core Duo
Motherboard Chipset: Intel Calistoga i945GM/PM
Hard Drive: 100GB 5400RPM SATA (Hitachi Travelstar HTS541010G9SA00)
Memory/RAM: 1GB (1,024MB) (configurable up to 4GB)
Screen: 15.0" 1400 x 1050 SXGA+ (LG Philips LP150E05 - A2)
Graphics: ATI X1400 128MB
Optical Drive: Multi-Burner DVD recordable
Battery: 9-cell (extended life, protrudes from back of notebook)
Wireless: Intel PRO/Wireless 3945ABG (802.11 a/b/g), Bluetooth 2.0, InfraRed
User Input: Touchpad, Pointing Stick, UltraNav buttons, Fingerpring Scanner
Warranty: 3-years parts and labor, 1-year battery
Dimensions:
14.1" screen config: 12.2" x 10.0" x 1.0-1.2" (width x depth x thickness)
15" screen config: 13" x 10.6" x 1.2-1.4" (width x depth x thickness)

If I can afford to go with the 7800 GPU, then I think I will. I'm leaning towards the MSI 1036, but I know the MSI 1039 is coming out soon w/the x1600 GPU in it, so I'll have to wait and see if it's going to be affordable for me.
So if I understand your information about the nVidia's 6600 and 6800, they are equivelant to the 6600GT and the 6800 desktop graphic cards? If that's the case, then the 6600 would probably be a smarter choice than the x700, since the 6600 should have the updated graphics engine. I know the x700 is really close to it, but if I can find a 6600 w/256mb of dedicated DDR, then I might go with it.
Do you know of any other laptops that would give me the best "Bang for the Buck"? I think I'm liking the 17" widescreen, because I play World of Warcraft and it would allow me more screen area to put all of the icons on it and still have room to spare for viewing. I might drop down to the 15.4 screen size if I have too, so I can get a better video GPU, but I'm not quite sure if that is possible.
I forgot to mention that here is some of the specs that I'm considering for the budget gaming laptop:
Processor
Intel Duo Core (1.6-1.7GHz range) or
AMD Turion ML 30 (1.6GHz) or ML 34 (1.8GHz)
Memory
1 Gig of DDR2 or DDR, depending on system requirements
HDD
60-80Gig 5400 or 7200rpm w/8mb cache
WiFi
802.11 b/g wireless (minimum maybe Blue Tooth too)
15.4" screen, but prefer to have 17" screen

All of this for <= $1,500

If you have any ideas, I'm interested. I know that the Intel's Pentium M's are good, but I'm not sure if I want to go that way since they are only 32bit processors and Windows Vista is coming out this year and should be 64bit capable. I'm generally leaning towards the AMD Turion, since it's 64bit and generally runs cooler plus the ML version is only 35W. Generally I plan on having the laptop plugged in most of the time, so if I can get about 2 1/2 hrs. or so from a charge, I think that should be good for me.