If you run you hosting on a Linux server, it normally comes out of the box pretty secure with few of the older less secure services enabled. On top of this, if you use a provider like AWS they further secure the server by their own custom firewall. I truly like Amazon Web Service and have used it for some time. They can scale from mom-and-pop shop right up to enterprise.
After 10 years of service, my old linux box finally gave up so I bought a basic tower to run Linux on. I've got to say that Fedora 19 was very easy to install and get working. Just as with Windows 8, I think the new Gnome 3 interface is an improvement once one is accustomed. Although I did tweak a few things with the tweak tool. These days, I use a setup of Win7/64 running on a macmini (you read that right - I run windows on my macmini).
I had an interesting issue with tomcat today on my VPS. I added a new domain to my tomcat server configuration, and accidentally caused a circular reference in the alias section of one virtual host to another virtual host. By this I mean that one virtual host configuration had the same alias as in another host. I am assuming this made some web applications load up more than once, and therefore the server use more memory than would normally be required.