Hope I'm not out of order here - I'm FraminGal's husband and a network administrator for a nearby college. My wife is always raving about the Grumble, how great you guys are and how much help she gets here. I'm pretty comfortable with computers (although I'm slowly losing touch with the standard desktop variety as I get sucked deeper into the black void of enterprise computing...). It's obvious that you have some computer literate folks here as well, but I wanted to toss in my two cents' worth in appreciation for your help with FraminGal's questions.
Regarding Pentium vs. Celeron vs. Athlon - David is correct. The difference between Pentium and Athlon is cache size which translates into Pentium being better able to handle a lot of number crunching. We're talking CAD, PhotoShop and heavy-duty graphic games. AMD has been giving Intel a run for their money lately with their Athlon chips - again, it's largely a function of cache size, although Athlon does process more data per clock cycle than Pentium or Celeron in some cases. The big question - will you see a big performance benefit for your money in day to day computing? Probably not. Save your money or put it in RAM (256MB or more would be a good investment) and maybe a bigger hard drive. How big is your current drive? Is it getting full? The answer to those questions should help you determine if it's worth your time to invest in a bigger drive. If you rip CD's and store your MP3 files on your hard drive, it's pretty easy to chew up those gigabytes. Don't buy the bottom of anybody's line - corners are cut to keep those prices low and this can often cause unforeseen problems.
As for brand name, FraminGal and I have a couple of Dell desktops, a Dell laptop, and half a dozen home built machines using both Intel and AMD chips. The college for which I work buys several hundred Dells every year. Overall, I'd say Dell's service is above average for a company of that size. Still, if you have a competent, reliable mom and pop computer shop available nearby where you can get good service, why not go with them? I can't speak for Gateway or Micron since I haven't had any recent experience with either. What sort of problem have you been having with your Gateway that they are unwilling or unable to fix?
Lastly, (then I'll shut up, I promise...) we've also had a RoadRunner account for the last three years or so. We use Verizon DSL at the frame store. RoadRunner has been amazing. I can count the number of outages we've had in three years on one hand, and the throughput is great. Be aware of the security implications with a cable modem or DSL connection though. RR is basically one big network to which you are always connected, and not all your Internet neighbors play nice. I would strongly advise using anti-virus software (and keep it up to date!) and some sort of firewall. Windows XP has a rudimentary firewall built in and there are other relatively inexpensive software and hardware firewall solutions available as well. Might be another good subject to bring up with your local mom and pop computer shop.
Okay, I've written a book. Time to sit down and be quiet. Thanks again for all your help (past, present and future) with the framing questions - we're really grateful!