I have been using Hetzner sine 2012 and I think I am enough acknowledged to write an review about them.
First i started hosting company using their dedicated server EX4 and i was quite satisfied.
BUT they have issue with hard drives, after several months of high usage of hdd one of them failed.
Luckily they have Software Raid 1, so you just need to contact support and they exchange defective hard drive within 20 minutes.
Then SW raid is synced again.
Another problem is, they do not have DDoS support, so usually when DDoS attack occurs they null route IP address untill attack stop.
But I got some information that soon they will get DDoS protection service 🙂
Performance of their servers is quite good and they are fast. I was amazed with i7-720Q processor i had on my server.
So, i recommend you using Hetzner A.G.
Another data center i have used is Online SAS France http://online.net and they servers are so powerfull and cheap.
But they support is really bad, unless you are willing to pay for it.
I hope you enjoy article, let me know what you think in comments bellow.