Any recommendations on a NAS for a home-super-user?

I bought a Readynas 4 years ago and I have been nothing but happy with it. Their current home/office products (the NV+ abd NVX) meet all your requirements, and then quite a bit more. Some features include:

• SSH access
• built-in bittorent client
• hot swappable drives
• file-services: CIFS, NFS, HTTP(S), FTP(S), AFP, rsync
• DHCP and printer server
• RAID 0, 1, 5 (and their proprietry X-Raid)
• USB ports
• a bunch of useful backup features
• simple or advanced user modes

Quite a large community has built up around their online forums, and I have been blown away by the level of support that their staff provide over the forums. They also release somewhat regular updates to the OS, which still apply to my old Readynas X6.

I have a Thecus N4100PRO at home.

• It has 4 bays.
• It supports RAID 0/1/5/6/10 and JBOD.
• It has 2 Gigabit Ethernet ports ==> It can be configured as a router.
• Also has USB ports on which you can connect
  • extra HD's (e.g. for backup purposes).
  • a printer (which then can be used as a network printer).
  • a Wi-Fi USB stick (with which you can use the NAS also as a Wireless Access Point).
  • a WebCam (with wich you can use the NAS as an IP CAM server).
• Its firmware is released under the GPL.
• There are some nice forums on which to ask questions.
• The functionality can be extended with other modules (there's even an IP CAM Module for extra security ;-) ==> see the point about USB above).

I personally have a QNAP on my network (4-bay model), and although mine had a relatively low-powered processor, there are models ranging all the way up to 2.4GHz.

Their support is excellent, and their forums are very helpful for doing non-standard things (hackers that set up SVN servers, media streamers, etc. on their NAS are not uncommon on there).