I just thought it was about time to share my experiences with AmenWorld.com. I have seen many bad things about them in this forum but personally have never had a problem with them.
I have had their cheapest dedicated offering:
AMD Duron 1600
Plesk Control Panel
since July 2004 (over 8 months now) and had no downtime. There was some network maintenance carried out for which I was forewarned but this didn't effect our server.
We've pushed over 300gb/month (yes i know this isn't a lot to some of you!) and can often hit over 2MB/s in europe:
12:46:30 (2.40 MB/s) - `LFSBOOK_ED1.iso.gz' saved 
Speeds to the US are usually a lot slower averaging around 200kb/s but for our needs this doesn't really matter.
The sales process was easy and the price was one of the cheapest i'd seen. If you're after a budget unmanaged server then I'd highly recommend them.
They don't provide any sort of upgrade ability although they do have higher spec servers.
They now provide online bandwidth usage tracking in their customer area so you know if you're going to go over your 1tb alotment. They do have lots of extra services which can be tagged on such as remote reboot ports etc (otherwise its an email to tech support who normally respond within 15mins but usually faster).
In short this was a really economical way to get into dedicated servers. There are slightly cheaper options out there but i'd highly recommend amenworld so far.
Hopefully i've answered many questions as there wasn't a specific review of them on this forum.
Any questions, post in here.