I'd likely take the Gateway one but let's note the differences between them:
CPU on Gateway is faster, more cache than the Dell one.
Hard drive is faster on the Gateway though the Dell has more room.
So while the Dell wins on the size of the hard drive, I would likely think the Gateway is the better system based on the given specifications which leave out the battery for each.
I'm lookin at 2 notebooks. One from dell, one from gateway. I'm really lookin for a notebook that will fare well for me for years and have some good graphics, be fast, but not be too expensive.
Inspiron E1705 ($2,033)
Intel Core 2 Duo T5200 (1.6GHZ,2MB L2 Cache, 533MHz)
Win XP Media Center
17" ultrasharp wide screen uxga display with trulife
2gb shared dual channel ddr2 sdram at 533mhz
120gb 5400rpm sata hd
256 nvidia geforce go 7900 gs
sound blaster audigy hd
internal a/g wireless
Intel Core 2 Duo T7400 (2.16ghz 667mhz fsb, 4mb l2 cache)
2gb 667mhz ddr2 sdram
17" wuxga TFT active matrix (1920 x 1200 res.)
100 gb 7200rpm sata hd
internal a/b/g wireless
nvidia geforfce go 7900 gs 256mb