Depends on ur useage and what u want it for.The Inspiron lineup is laptops only,The 420 is a good machine and will do alot of work and also play.If you think you ever might need the extra power and also furture upgradablity maybe a used one off the outlet is your choice710 or 720.But that420 is a fine machine and either way you go ull love either or.

Just for the record... the lower end Home desktops are now Inspirons.  So not just laptops by that name anymore. http://www.dell.com/content/products/category.aspx/inspndt?~ck=anav&c=us&l=en&s=dhs&cs=19

 

Based on the list of activities you'd use it for, I'd say the choice is between the Inspiron and the 420.  The 720 would be over the top for you unless you're going to start gaming and doing lots of video editing.  Just avoid the slim version and go w/ plenty of RAM (2GB+ @ 800MHz).  And I see they now offer an E6xxx series Intel processor, which is a good thing.  But if you do much tweaking to the Inspiron, then you're nearly to the price of the 420, and a few extra bucks gets you a newer/stronger chipset and some nice bells and whistles.  Personally, I'm going 420 w/ quad core and 2GB 800Mhz ram.  It should last me 4-5 years and have good upgradability and expandability.  (One note on expanding... fewer PCI slots than your Dimension probably had but more things are coming out w/ a PCI-e version and both Inspiron and 420 have one or two open PCI-e slots to work with).

 

It definitely looks like the 420 is the way to go for me.  Thanks for the input.