I've had a colo server with QuickPacket (quickpacket.com) for just about ten months now (I started in January, 2006). I've got the $49/month "special" plan which they've been offering for quite some time now.
Support is fast, efficient, friendly, and competent. In a fit of stupidity, I shipped my box with a misconfigured sshd, which prevented me from logging in. QuickPacket's support fixed the problem promptly. My plan isn't managed, so I was expecting to be charged a bit. But no charge ever showed up. I'm fairly sure that was on purpose just because the support team is awesome, but just in case it wasn't, shhhh.
Latency and throughput are both great (my server is at imsanet.org if you'd like to ping it; it's used mostly for email at the moment so throughput isn't as testable - but trust me, it's every bit as fast as the 1 mb port you're plugged into).
I've had no downtime that wasn't self-caused (rebooting to install a new kernel, etc.).
In short, they're the best hosting company I've ever worked with, and I'd recommend them highly. I'm considering signing up for a second account a few months down the road to add online backup and redundancy. At the time I signed up, they had the best deal around for what I was looking for, and I suspect that's probably still the case.
ebowden, thanks for the headup and welcome to WHT! Great to see Quickpacket's positive reviews this year except last year for few outrages. I'm sure they have improving the services!!
I have ordered server reserved today at QuickPacket, can't wait to use their services for the first time. Their billing responsed few mins after I declined Fantastico, they'll put a credit on my next month bill - good idea