Dude ! Im gettin a D3LL !!!!!!!!

Hopefully someone can tell me which system they think will last longer,and is a better deal. I will be using it for school mostly and maybe some media activities, I have $600 and a sack of coupons to spend, give or take almost nothing.
I was looking at the Inspiron B120 and 130 series, and was Uninspired.
Ive heard the Latitiudes are nicer than the inspirons, except for the 6000. Inspiron 6000
Intel® Pentium® M Processor 735 (1.70GHz/2MB Cache/400MHz FSB), Genuine Windows® XP Media Center Edition 2005
$699
Ok so Should I get that or the Latitude D510
Intel® Celeron® M Processor 370 (1.50GHz) w/ 14.1 XGA Display, Genuine Windows® XP Home Edition, SP2, with media
for $606 after coupons and discounts , or should I get what I really think will be good as far as future applications go, even though its not 64 bit, I like the E1505 Dual Core Intel® Core™ Duo processor T2300 (2MB Cache/1.66GHz/667MHz FSB), Genuine Windows® XP Media Center Edition 2005 for $699.
Well then,
Hope this is enough to go on, im thinkin alot about that Dual core model though, let me know what you guys think, and thanks in advance !