I have an installation of PC Linux OS 2007 atm and I like it a lot.
It loads with full office facilities and all codecs to play music files and DVD movies. Installed UT2004 no probs, it pretty much worked for me straight out of the box, so to speak.
Here's brief specs what it's running on, I'm using a series of swappable (internal caddy) PATA hard drives for different OS's, PCLOS2007 is running on an 80Gb drive.
Aopen MX46 motherboard circa 2003.
Celeron 1.7Ghz
1Gb PC3200 memory (DDR, 2 x 512Mb)
Nvidia AGP 6800 256Mb video card
350W PSU
Asus DVDRW
A Floppy drive
Netgear LAN Card
Creative Audigy 2 Soundcard
PCLOS2007 detected the lot and connected online straight away.
I tried the last distro of Ubuntu and didn't like it much, had a couple of problems as well, as I recall.
I do like Suse but it's very bloated and doesn't come loaded with Codecs. If you want to play music and DVD's you'll have to search the net for solutions. There are several guides out there though and it's straightforward enough, using YAST to make Suse Media friendly. Well at least I found it so. Last distro of Suse I tried was V10.1. Since then there have been 10.2 and 10.3.
I do like Suse though, despite it being huge and needing configuring, it looks gorgeous and if it's your thing then it's the closest to Windows that I've tried of all Linux Distros.