Upgrading of Computers.--> Emachine T6212

Well, some people have asked me; "Are you really going to upgrade an Emachine?" Why yes I am is the reply. As I do this, I will give my thoughts of the parts that I use. Pros and Cons. I do hope it will help someone on a part they are thinking of buying.
This is what I started with...

Specifications

CPU:	AMD Athlon™ 64 3200+ Processor (with AMD 64 technology) (2GHz, 2000MHz System Bus, 512KB L2 cache)
Operating System:	Genuine Microsoft® Windows® XP Home (SP2)
Chipset:	ATI Radeon® Xpress 200
Memory:	512MB DDR (2 × 256MB), 400MHz Dual Channel Expandable to 4GB
Hard Drive:	160GB HDD – 7200rpm, 2MB cache
Optical Drive:	16x DVD±RW multi-format double layer; 48x CD-ROM
Media Reader:	8-in-1 Media Reader Secure Digital™ (SD), Smart Media, Compact Flash, Micro Drive, Memory Stick®, Memory Stick PRO, Multimedia Card, USB 2.0
Video:	ATI Radeon® Xpress 200 (PCI-Express® ) 128MB shared video memory
Sound:	6-channel Audio
Network:	10/100Mbps built-in Ethernet
Modem:	56K ITU v.92-ready Fax/Modem
Peripherals:	Premium Plus Multimedia Keyboard, 2-Button Wheel Mouse, Amplified Stereo Speakers
Ports/Other:	7 USB 2.0 ports (2 in front; 4 in back; 1 in Media Reader), 1 IEEE 1394 port (1 in back), 1 Parallel, 2 PS/2, Audio-In & Out
Dimensions:	7.25"W x 14.125"H x 16"D