The desktop... I bet your desktop would take out my PC in a heartbeat though.

AMD Sempron 2600+ 1.81 Ghz
Biostar NF325-A7 motherboard.
Maxtor 40 Gig HD
Viewsonic 19 inch Hi Def Wide Screen 5ms LCD monitor.
1 gigabytes of ram.

... BUT, my monitor rules ALL.

You could always use a program such as FRAPS >> http://www.fraps.com/ and record frames per second tests on both of your machines when playing Counter-Strike to see which one outperforms the other.

For games, I would take the desktop- though I would upgrade to a dual-core and perhaps a 7600gt card if available. The laptop has a better cpu but half the RAM and integrated graphics. With Vista, you want as much computer as you can get and then some.

this is what I have so what is better

2 x AMD Opteron(tm) 285 64Bit Dual Core (DC250) 2048KB Cache 2 Way HyperTransport(tm) $2.199.00
16384MB DDR 400MHz PC3200 Registered ECC Dual Rank Interleave req. 2 CPUS3.899.00
2 x nVidia Quadro FX 3500 256MB DDR3 PCIe 2x DVI Dual Link SLI CapableS1.779.00
32" X32SV-Naga II Sceptre Wide LCD-TV 8ms. 1366x768NRS819.00
160GB 7200RPM SATAII 300MB/S 8MB Cache 9ms avg seek Optional 160GB 7200RPM SATAII 300MB/S 8MB Cache 9ms
Optional 160GB 7200RPM SATAII SOOMB/s 8MB Cache 9msS79.00
Optional 160GB 7200RPM SATAII SOOMB/s 8MB Cache 9msS79.00
HD Ctrl. According To Motherboard and HD Type Selected
DVD+RW/DL/+R-R/CD-RW SONY DW-Q30A Double Media 4.7/8.5GB 16x w/SW-media$69.00
DVD+RW/DL/+R-R/CD RW SONY DW-Q30A Double Media 4.7/8.5GB 16 w/SW-media$69.00
1.44MB 3 112" Floppy DriveSO.00
CreativeLab X-Fi Elite Pro 7.1 24bit Digital SoundS369.00
On board 1GB Ethernet (10/100/1000) on board LAN
Creative Lab Inspire T7800 7.1 90W RMS Positional EAX Digital 7P+ SubWS89.00
Logitech Deluxe Black Windows Keyboard
Logitech 2+ Wheel PS/2 Mouse Black Optical w/Mouse pad$0.00
Genuine Microsoft Windows XP Professional-64 CD-ROM w/manuals/act.reg."S69.00
Logitech WingMan Formula(tm) Force GP Steering Wheel w/Pedls.S69.00
Supermicro H8DCI Nvidia NForcel Pro 2xPCIe SLI cap.3xPCIX IxPCIe x4 to 16GB S49.00 DDR400 2xG.Bit Lan. SATAS.OGbps RAIDO.1,0+1 6Ch. Audio.
600W OCZ GameXStream(tm) Quiet 12cm BB Fan PowerWhisper(tm) ULS65.00
Three Years System Parts & Labor + Three Year On Site ServiceS259.00
Xi MTower ATX Black-Silver T-Free-Lock Top USB/1394-12 bays-460W- 5xBB Fans. $0.00
Sub-Total: $11,658.00
Discounts: $ 233.16
After Discount: $11,424.84
CA Sales Tax: $0.00
Shipping: $ 265.84
Quantity: 1