Need Some Advice - Best Distro For My System

Hey guys, this is my first time posting here (although I've been reading the forums for a while now). I'm looking for a good UNIX (or UNIX based/UNIX-like) distro to install on an old Dell Dimension 2400 Destop. I've done ALOT of research on the different distros and I've tried a few out but I was wondering which would be best for what I want to do. I want to use the machine for programming, light internet/e-mail use, and web design. A nice, clean, customizable (but semi-lightweight) desktop environment would be ideal. It's hard finding distros compatible with my machine, but here are the ones I've tried:

- FreeBsd 9.1: This was the most successful one so far. Everything went smoothly but Xorg was very bland and installing Gnome or KDE on it didn't work either. If I had to go back to this I would.

- Ubuntu 12.10: Gave me so many issues. Came to the conclusion my machine was to old to run it.

- Mint 14: Same as Ubuntu. Did not work.

- Xubuntu 12.10 - Currently running. Not 100% impressed, a little sluggish.


And here's my computer specs:

Processor Intel(R) Pentium(R) 4 CPU 2.53GHz
RAM 1 GB

PCI Devices

Host bridge Intel Corporation 82845G/GL[Brookdale-G]/GE/PE DRAM Controller/Host-Hub Interface (rev 01)
VGA compatible controller Intel Corporation 82845G/GL[Brookdale-G]/GE Chipset Integrated Graphics Device (rev 01) (prog-if 00 [VGA controller])
USB controller Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #1 (rev 01) (prog-if 00 [UHCI])
USB controller Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #2 (rev 01) (prog-if 00 [UHCI])
USB controller Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #3 (rev 01) (prog-if 00 [UHCI])
USB controller Intel Corporation 82801DB/DBM (ICH4/ICH4-M) USB2 EHCI Controller (rev 01) (prog-if 20 [EHCI])
PCI bridge Intel Corporation 82801 PCI Bridge (rev 81) (prog-if 00 [Normal decode])
ISA bridge Intel Corporation 82801DB/DBL (ICH4/ICH4-L) LPC Interface Bridge (rev 01)
IDE interface Intel Corporation 82801DB (ICH4) IDE Controller (rev 01) (prog-if 8a [Master SecP PriP])
SMBus Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) SMBus Controller (rev 01)
Multimedia audio controller Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) AC'97 Audio Controller (rev 01)
Modem Broadcom Corporation BCM4212 v.90 56k modem (rev 02) (prog-if 00 [Generic])
Ethernet controller Broadcom Corporation BCM4401 100Base-T (rev 01)

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SCSI Disks

ATA ST340014A
HL-DT-ST DVD-ROM GDR8163B
SAMSUNG CD-R/RW SW-248F