I Edit alot also, i use Premiere Pro, Sony Vegas, Pinnacle Studio and After Effects.
I tend to mix it up between the lot for different effects and trasactions but i mainly stick to Premiere as i have the better knowledge with that software.
My Computer Specs:
ASUS 993 Motherboard
AMD Athlon 64 3800+
1.0Gb DDR RAM ( Best to have 2.0GB Havnt got round to it yet )
512Mb Radeon X800 PCI-E
At the moment using just 1 19" W/S But grabbing another one in a few weeks to help out with the workspace of editing.
1 x 250GB Porche Externam HDD (for Video data)
1 x 80Gb SATA Hard Drive (for Video data)
1 x 180Gb SATA Hard Drive (Boot)
On-Board Sound Card 7.1
7.1 Logitec Speakers Surround Sound (Not to sure of the model)
Firewire Card
Basic DVD RW think its Sony or Samsung
These are basic specs and run all the software i know of smooth and effeciently.