Most suitable Linux distro for a ~2003 laptop

"Well, I ended up going with Windows 7 - I found some articles about 7 being better than XP on older hardware and gave it a try.

And it is amazing - it flies along compared to the old XP install (which was pretty fresh anyway so not suffering from the usual long term XP install issues)

Missing loads of drivers on first install including the NIC but after I added the Broadcom driver Windows Update found all but the Audio and the Dell XP driver works fine for that.

I'm pretty happy with it now. Thanks all for your suggestions."

"Two alternative ends to a range of choices like other answers here suggest.

Ubuntu (preferred for its Debian support)
PuppyLinux (in case Ubuntu is not fast enough for you)

Some suggestions,

Try to install the OS on a flash-drive rather then trying it from a LiveCD
Observations from a LiveCD trial may not match those you should expect from an installation.
IF you like the USB-install, you could continue to use it for a while before completely changing over to a laptop installation.
Optimize -- by reducing unused stuff running in your default installation.
Also consider remaining on lower graphics modes (less effects) initially; then enhance effects if things work smoothly.

As a reference,

I currently run Ubuntu on a 7 year old D800-512MB-nVidia laptop -- from a USB flash.
No trouble with stability -- though, I could use some more RAM for smoother operation.
Have managed to recover completely after accidentally removing the flash too."

"Try MacPup ""Opera"" or ""Foxy"" (Tagline: A Beautiful Remaster of Puppy Linux) depending on your browser preferences, but the ""Opera"" release got the better looks :)

It's a rather small download (130-150 MB) and you can run it as Live CD first to check the hardware compatibility."

"You can fine tune nearly any Linux to run more lightly if you want. You might be best served picking a distro you already have some familiarity with and stripping away the things you can live without. If you don't want to put that sort of effort into it, then I would recommend Crunchbang. It's Ubunutu based & gives access to an impressive software repository, but uses a lightweight highly configurable window manager - Openbox. You can to 'roll your own' by installing a standard Ubuntu & then installing and cofiguring Openbox yourself, but the Crunchbang folks have done alot of the homework for you. They also include quite a few lightweight alternatives to the standard music / mail applications typically found in Linux distros.

It's almost as lightweight as Puppy linux running the e17 window manager, but has IMHO much better software selection.

One caveat: if you don't like the command line, then forget everything I've written here & pick something else ;-)

As The Journeyman Geek suggested, try out the Live CD's first & see which you like.

As an aside, I have Ubuntu 9.04 installed on a cheap e-Machines laptop I bought new for US$220. It's about as low end as you can get - she is very rough on hardware. My daughter uses it to check email, surf the web (facebook mostly) & listen to music, local and streaming. Believe me, if it wasn't working, I'd hear about it!"