$600 bucks should get you a nice laptop! I just wanted to chime in to say good luck with your search. Kind of made me remember the advice you gave when my Subaru repairs were going on.
Like you said before, I also like to buy above entry level computer hardware. I think it performs longer as technology advances every two weeks.
We got my wife a Compaq (HP) 17" widescreen with ten key laptop a year or two ago, running vista. No problems so far. Pentium dual core 2 or some such thing... When you see dual core or quad core, think single processors stacked on top of each other and capable of doing the work of each at the same time - because that's what they are.
I still believe in Intel processors after almost twenty years of computer use. I was a apple guy before that (motorola processors).
Anyway - best advice I can give you is to pick a dollar amount you want to spend, that's the starting point of your search. Then go out and look at laptop reviews on CNET and PCWorld etc. Look at reviews that fit the type of machine you will be using. Look for the most RAM memory and larger hard drives, look for at least 7200 rpm SATA hard drives because they are faster accessing and writing data, should also come with a DVD read/write drive (they are backwards compatible to CD's etc.)
In a nut shell, think about what you'll be using it for... Are you blind? Get at least a 15" monitor... Don't worry if you find a good deal on a Vista operating system machine. The magazines are saying free upgrades might be in the works to Windows 7 but the IT guys I know are all throwing fits trying to figure out Windows 7. As a consumer we just don't know if its stable yet because its so new. Again, read reviews...
If you like high resolution images/graphics to maximize usage of your desktop real estate then look for a good video board. But most state a specific video chipset that is on the motherboard like its something special. The key is to look how much video memory it has.
If you are a gamer, a video card upgrade is essential. Watching movies etc. the stock video is fine.
If you run a laptop off of batteries, look for at least a six cell battery to get you into the 2+ hr range.
Wireless is pretty standard now
I don't know if any of this makes sense or is helpful but I hope so. The other thing you can do is go to a Best Buy type of store or Costco or something and actually play with the machines. See which one jumps out at you and then see if it meets your basic criteria but most of all pricing for your budget.
Make sure you bone up on research regarding processors (CNET etc.) You can get a lickity split above entry level machine for just a few more dollars that will keep you happy for at least a couple years. Good processor/lots of memory/big and fast hard drive.
Personally, I hate all the crap software they put on new machines. I delete most of it and only keep what I use, add Office, some photo stuff, my mapping stuff etc. That's pretty much all I use... Oh, surfing the internet nowadays is pretty much determined by your internet provider access speed but also RAM memory, another good reason to have at least 4 gigabytes.
Best regards,
griz