Sticking with Apple is always a good decision, unless you're into playing videogames on your computer.
I'd recommend that you buy either a Macbook or a Macbook Pro. The Macbook's are smaller than the Macbook Pro's, but at the expense of the quality of the graphics card, which may impact you if you plan on playing games or running some video and animation applications like Apple's Motion or Adobe After Effects. But either machine is more than adequate for editing video (and I say that as a professional video editor who owns one of those ridiculous 8-core MacPro desktops with 16GB of RAM). Even a G4 Powerbook is good enough for most video editing tasks. I cut over 40 weekly TV shows on my trusty old 12" Powerbook G4, and that machine is slower than Gorch's Rascal. My Macbook Pro is 3-4 times faster than that Powerbook, just for perspective.
My biggest recommendation is that you max out the RAM in any laptop you buy. That, combined with the size and speed of your harddrive, are the 2 biggest factors in laptop performance. The CPU speed, relatively speaking, don't mean shit if your harddrive is slow and youre constantly running out of RAM. If you buy one of the new Macbook Pros which Apple released within the last few months, you can install 4 GB of RAM in it, which makes a world of difference if you're editing video, or just doing general multitasking. My first generation Macbook Pro can only have 2GB RAM max, and as you can see in my menubar from the
Post Your desktop thread, my RAM usage is always pegged out. I constantly long for 2 additional gigs of RAM.
Speaking of which, DO NOT buy your RAM from Apple. Just spec out your machine at the Apple Store with the least amount of RAM possible, then purchase your RAM from a 3rd party vendor, such as
Crucial or
TransIntl. Apple royally rips you off in this department. I saved almost $3000 just by buying my 16GB RAM upgrade from TransIntl, instead of Apple!
The biggest advantage to buying a new Intel based Mac, besides the superiority and stability of Mac OS X, is that you can run WindowsXP/Vista on the same machine, either by installing it natively onto it's own harddrive partition using
Boot Camp (which requires a reboot everytime you want to run Windows), or right within OS X, using a "virtualization" program such as
Parallels Desktop. The speed of Windows using something like Parallels is just as fast as a "real" PC for most things. In fact, I used to edit the Best Show podcasts on my Macbook Pro using Sound Forge (Windows only) running on Parallels.
Refurbished Macs are just as good as "new" Macs in my (and the
majority of others) experience. They come with the same 1 year warranty as new Macs, although I ALWAYS recommend purchasing the Applecare warranty extension with Mac laptops. It's one of the rare cases when a manufacturers "extended warranty" offer is worth it.