Buffalo is to be avoided. Their stuff is typically crap, at least on the NAS side of things.
Do *not* go for a Dobro either. They're slow as hell and use a proprietary RAID-emulation layer which encrypts your files. Too many Dobros just plain die a quick death and the files stored on the HDs can't be rescued as a result of the encryption.
For a good NAS, your 2 major players are Synology and QNAP.
QNAP has a huge load of handy utilities for their NAS devices programmed by regular people like you & me. If you plan on doing loads of tweaking and using every possible capability, the QNAP devices are impossible to beat.
Synology has a different philosophy that caters more towards the user who doesn't want to fiddle around too much, even though their products also have a wide range of capabilities and possibilities. But the ease-of-use and the intuitive 1st-time setup are painless and quick.
I personally went with a Synology DS411 : Invalid Link Removed
I do regret it one bit.
HOWEVER!!
Remember the following since most people forget ;
- You need a gigabit NIC on any/every PC in order to benefit from the transfer speed.
- You also need a gigabit router.
Otherwise, transfer speeds will have a ceiling of roughly 28mbps. Transferring, say, gigs of data will take a loooong time.