If you want a personal testimony, read here. If not, it's tl;dr
It depends, really. The more you pay typically the better dedicated server service you get.
Talaturen recommended
this hosting service a while ago. I'm not sure if he feels the same way now as he did then, but I trust his judgement when it comes to anything related to OT.
Talaturen did recommend Server4you to me about a year ago or so. I spoke with him recently and he agreed with me that they offer you
nothing when it comes to DDoS attacks, so you're pretty much SOL there. BUT, their servers are very cheap for what you get!
I've never used ChicagoVPS (but since a lot of trustworthy* people are suggesting it, it's probably a safe bet).
I've found a great balance between personal service, and price with
Unmanaged Dedicated Server Hosting in Dallas, TX | Limestone Networks
They respond to tickets within 30 minutes usually (my average has been about 4 minutes) and they do
not offer DDoS "protection" but they automatically try their best to protect you from attacks (which is better than Server4you/Hetzner).
All in all, if you decide you like Limestone Networks (like I do), please use
this link. I've never referred anybody but I'll let you know how they repay people for referring them.
Although, this is not about that. I've hosted one server for over three years. I've used VPSland, Serverloft, Server4you, Hetzner, and Limestone Networks, and I suggest Limestone Networks

Best of luck finding a server to host with!
Red