Depends on what you're trying to do. I run a small domain on a T1 without pictures or audio, so I'm using a Raspberry Pi 3 as a server. Quite a bit faster than the old PDP-11s the 'Net started out with, and significantly less expensive. And smaller.
My domain used to be a lot larger, but still a T1 and very little video/audio. I used the bottom-of-the-line Dell servers back then, and bought my own RAM (Dell gets a lot for a RAM stick). The biggest advantage to the Dell servers, aside from the reliability of the components (over 15 years, I never had one fail), was that they could be bought without the Windows tax. If you're looking to do a full blown Google level server on a 10G connection, advice there is above my pay scale... -- Glenn English