The Vostro 1500 seems pretty good:
ntel® Core™ 2 Duo Processor T7250 (2.00 GHz, 2 MB L2 cache, 800 MHz FSB)
Genuine Windows® XP Professional
15.4" Wide Screen WXGA (1280 x 800) Display with TrueLife™
2048MB 667MHz Dual Channel DDR2 SDRAM (2x1024)
160GB (5400RPM) SATA Hard Drive [Included in Price]
256MB nVidia® GeForce® 8600M GT
Fixed Internal 8X DVD+/-RW Drive
Primary 6-cell Lithium-Ion Battery (56 WHr)
for just under £600