hey ya'll, this weekend I'm going to be installing XP on a few of my machines that don't already have it (and one I'm probably going to be going back to XP with, after trying 7).
I was wondering what programs do you recommend using for a better experience?
here are some specs of some of the machines
intel 1.4ghz dual core 1gig ram dvd drive, built in webcam, laptop - used mostly for playing text twist and the sims and the sims 2.
intel 2.4 ghz quad core, 3 gigs of ram, dvd, bluetooth - used for games, video editing and capturing
intel 2.4 gigz dual core, 2 gigs of ram, dvd, built in webcam, bluetooth, laptop - used for games, video editing and capturing
currently the first 2 computers are using vista, the first one gets so choked up, it's not even funny. the second one actually runs quite fine, I'm just expecting a performance increase with it.
the first one is my girlfriends comp (if you couldn't tell, hahaha), so I'm not looking for anything too complicated on there, she knows some things and isn't ridiculous, but she just doesn't have much of a need for a comp. I've also suggested using firefox, but she declined.

Ccleaner for cleaning windows
Find and run robot for launching apps
Xnview for viewing images
VLC for video playing
Foobar 2000 for music playing
Those are all free.

As far as firefox goes, I think you can get themes and set it up to look and act more or less like IE, if she doesn't think she'll be able to get used to something new.
Have you considered putting the Windows 7 beta on one of your computers? Microsoft are handing out keys, and you have a couple of weeks to download the ISO from them directly - after that you can apparently still get keys, but have to find the ISO yourself. It expires in August.
From what I hear, it's a massive improvement over Vista, scales nicely to different specs (down to netbook levels, with far better performance than Vista), can use Vista drivers, and... well, you do have two non-girlfriend computers, so you could try experimenting a bit. If nothing else, you should notice a performance boost.
And it's free (for now). And if you don't like it, at least you've staggered the reinstalls so you're not setting up two XP machines at once. You can get one nicely configured with all the software you end up wanting so you have an easy time duplicating it on the other. Or something like that, I suck at convincing people to do things.
I'd do it myself, but I only have the one desktop, and my eee runs linux.
Edit: Apps!
AVG, Ad-Aware, Spybot. 7-Zip. Pidgin for IMs. uTorrent for downloading stuff from Public Domain Movie Torrents. VLC for playing videos without codec hassles, if something won't play in your main player.

hmm... what exactly do you mean by 'better experience'?

Wow, I've never heard of that site before, they actually have Reefer Madness, one of the greatest (and worst, at the same time) anti-drug movies ever!

Avira AntiVir Premium, the best antivirus of 2008 according to AV-Comparatives (free 6 months license here, ok stop spamming :-P).
ZoneAlarm free to let the hackrs f*ck themselvs :-P
Spyware Terminator. That's neat: it is an anti-spyware with real-time defense enabled (useless if use Avira Premium), but the feature I like the more is its Host Intrusion Prevention System (HIPS) shield which, if instructed to do so, won't let run any new executable file on the system without your consent.
These are my three "essential" things to install on a fresh XP system.

as described above, the one I'll be returning to xp with, is my macbook, I'm going to do some benchmark tests with windows 7 and then probably return to xp.

I agree with much of that list, but... AVOID AVG AT ALL COSTS. It's detection algorithms aren't very good (and this is me being extremely polite), it likes to generate a lot of false positives, this I know because at nearly every software/hardware company I have worked for, at some point AVG has become a thorn in our side.
Use ClamWin instead: http://www.clamwin.com It's also free, and unlike AVG it's open-source.

I have to strongly disagree with that. I used AVG for years, both at home and in a corporate environment and it worked better than most of the "top shelf" commercial products out there (most especially Norton and McAffee). My only complaint with it is it is too resource intensive, hence why I now use Avast! Antivirus on my home machines (also free).

a friend of mine is requesting I reformat his computer as well, typically I've been using the mcafee that's provided to me at no-cost via my isp (it pays to work for a cable isp), just because I've been lazy, usually though I don't use any antivirus, but anyway, he had some issues with it, and I had used AVG because I couldn't think of anything else at the time, it didn't fix his issue (he had downloaded some random rapidshare file and got a virii) anyway, I'm going to try clamwin because I really like opensource software.. if I like how it works on his comp, I'll see about using it on my others.

I'll agree it's less bloaty and more useful than Norton/McAffee, but that doesn't mean it's not garbage, believe me, it is. I guess it depends on what kind of software you run/install however; if you've never come across it telling you that an installer you're trying to run contains a virus/trojan when you know it doesn't (say, for example because it's a freshly released internal build of something) I can see not having complaints about it. For me though? I wouldn't wish AVG on my enemies (though it is, as you stated, still better than norton/mcaffee)

I use Avast! as well. Used to use AVG, but switched to Avast! a while ago.
Other apps I get immediately on a fresh install (aside from overclocking related apps) are Firefox, Thunderbird, JKDefrag, AdAware, SpywareBlaster, Open Office, Gimp, and LeaveMeAlone! Oh, and since I've moved to two monitors, I also grab Display Fusion.

I switched to Avast! from AVG when AVG introduced their useless, resource-hogging LinkScanner in version 8.
Clamwin doesn't have an on-access scanner (yet) so it isn't as complete an AV solution as the other freebies that have been mentioned.
As for general-purpose tools, I highly recommend , and its cousin, the Firefox extension [url=http://labs.mozilla.com/2008/08/introducing-ubiquity/]Ubiquity.

THIS. Marvellous little thing, does a better job than the alternatives I've tried.
I moved to two monitors. At first, it was wonderful - I could watch a video on one and have everything else on the other, or keep something I wanted to keep an eye on off to the side! I tried going back to one, and while I can handle it on a laptop (especially with virtual desktops to switch between) it's just not something I can live with on a desktop any more, at least for heavy use. So I went back to two, but seeing how big the difference was when I didn't have two any more made me wonder what I was missing...
I'm on three now. I'm seriously considering more, or at least upgrading the ones I have.
Three and a laptop, half the time.
Weclock: The best thing you can add to improve your computing experience is another monitor. Just having a larger monitor, or a widescreen one, isn't the same as two independent ones. Do ittttttttttttt. Your girlfriend will understand and not complain about you buying more! And if she does, bah, take her monitor. If you already have multiple monitors, please disregard this. :P

Yeah, I tend to avoid using junky bits like that.
Ouch. In other news, it's less evil than the Hitler, cooler than the Sun, and cheaper than a PS3.

Hey! I didn't say that, AoE did.
I haven't tried that one, but I do use DeFraggler, from the same people who brought us CCleaner.