I vote supermicro. I've got a x10sl7-f and it's never once had a monitor hooked to it. IPMI sure is nice. Very reliable. Only time it ever goes down is when I reboot it.
I'll second Supermicro, that's all I use.
I know this is an old thread and for some reason it takes a lot of time for new members to get posting privileges. I pretty much gave up on this forum and surprisingly I got my registration e-mail last night.
As for NAS and servers, I went the opposite way, I went backwards by using D525 Atom processors based 1u servers due the low cost of ownership and small footprint. These take 20W max. I gave up on using full blown Xeon servers and rack cabinets for 24/7/365 home use as the electric bill was killing me. I'm using two of these right now that I bought used on eBay.
http://www.supermicro.com/products/system/1U/5015/SYS-5015A-EHF-D525.cfm
One is for my pfSense router which has 4GB RAM, 80GB SSD, and an additional 4-port 1Gbit Intel network card. Total overkill for home use using VPNs and other features, but 100% reliable and trouble free, Plenty of room for growth. Total cost $250.
The second one is for freeNAS. Came with 8GB RAM and 1TB harddrive. I bought a cheap PCIe CF card adapter and used an old CF card I had in my junk drawer. This is used for a media server with Plex and also as a NAS. Works nicely for streaming movies and MP3s. Painfully slow when doing administrative tasks, which you don't have to do that often when it is set up like you want. Total cost $225.
These boxes have been extremely reliable and haven't been shut off until yesterday when the utility company changed the transformer on our street.
Eventually I would like to upgrade to a Supermicro C2758 based Atom 1u server once they become available on eBay for under $200. They still sip 20W of electricity, which is very important to me.