Well I have ran ubuntu, fedora, and centos servers. I have just been jumping around trying to find a good one. The latest I have is CentOS, but I took the easy way and used XAMPP for its web server. Someone told me now that SME server is the best way to go. It is suppose to have apache, php, mysql, and a web administrative interface all configure right out of the box. From my knowledge it looks like it is RPM based and uses centos repositories.

So do you think it is worth making the switch to SME server? Or should I stay with my noob-configured centos server?

If you say you ran servers..this means that you have some knowledge about configuring linux.
Xampp is a good tool for web programmers..for system administrators...is best to get your hands dirty by configuring services.
I've seen a few CentOS servers..so if you want a stable web server go for CentOS.

This doesn't mean that SME is no good !!
You can always install webmin or ISPConfig to administer apache etc.. so the choice is there..

For example in debian all you need to have a basic LAMP environment is ..
aptitude install mysql-server apache2 php5 phpmyadmin

so I think you should go for some manually configured system :P

All right, I think it is best for me to manually configure them anyway. I will probably end up going with a debian distro. Although I want something that is stable, has high performance, and is secure. Any suggestions?

Use CentOS