Ok, so I finally have what I consider to be a respectable home theater. I'm still working on converting my TV and Movie collection for use on my HTPC. Going through Doctor Who (2005 forward) at the moment. Battlestar Galactica (the new one) is next.
I started off this year with a little 24" LCD alongside my HTPC, but I finally upgraded to a decent 37" Vizio.
Here are the specs:
Home Theater:
Vizio SV370XVT 37" LCD
Logitech Z-5500 5.1 Speaker Set
Roku (was the middle model before the new ones came out)
Logitech Harmony One Remote
Logitech K340 Keyboard
Logitech V450 Mouse
Dell Infrared Recevier
8 Port Gigabit switch
HTPC:
Intel Q9400 Core 2 Quad 2.66Ghz CPU
Asus P5QL Pro Motherboard
4GB (2x2GB) OCZ RAM
Radeon HD 5670
Coolermaster Praetorian Case
LG Bluray/HD-DVD Drive
Samsung DVD Burner
Windows 7 Ultimate 64 Bit
NAS: (where all my media is stored, in my computer room)
Jetway NC92-330-LF Dual Core Atom Mini-ITX Motherboard
Chenbro ES34069 Mini-ITX Home Server/NAS Case
80GB Seagate 7200RPM 2.5" Hard Drive (OS)
Highpoint Rocket Raid 1740 SATA RAID Card (PCI)
4x 1.5TB Seagate 7200RPM Barracuda Hard Drives in RAID 5 (~4.1TB total space. about 10% left at this point)
The Dell Infrared Receiver is actually part of a home theater set that came with the XPS laptop I have. The set includes a WMC Remote and a digital tuner, but the tuner I've never been able to get working completely.
Runs XBMC (Aeon theme) primarily. I just got my Harmony remote programmed to control XBMC fully using Evenghost. I can fully use XBMC without touching either the keyboard or mouse (including starting up XBMC). The infrared Receiver works great and combined with Eventghost to send proper commands to XBMC...it does a great job. Only remotes I use on a regular basis are the Harmony One, the keyboard and mouse (when doing stuff outside XBMC), and the lenovo remote (when laying on the couch and doing stuff outside XBMC).
Receiving local channels via ClearQAM over my cable connection. I don't pay for cable tv though, I just use what Comcast puts out with my high speed internet (12/2 business class).
My only issue with this setup is that the speaker system is hooked up via Optical from my TV and it doesn't always put out center channel sound in some cases. Most of the time it's a commercial though, so it's not a major problem.
Also have Boxee on the HTPC, but I use XBMC the majority of the time. I definitely don't like boxee for my movies and tv shows that I have stored on my NAS as it ended up replacing a lot of the artwork I associated with the shows using Ember Media Manager. I still haven't fully gone back and set them all back to what they were supposed to be.
Planning to upgrade my NAS to an ION motherboard and use it as my HTPC instead. The Quad core is nice, but can be better used elsewhere (dual box gaming).

A shot of XBMC running on the HTPC

Shot of the HTPC's Desktop, yes it's named ODIN

My Entertainment setup

the HTPC

Inards of the HTPC

Remotes: Logitech K340 Keyboard, Logitech V450 Mouse, Roku Remote, Logitech Z-5500 Remote, Logitech Harmony One, Lenovo HTPC remote, Vizio TV remote

Left side of the TV: Dell Infrared Receiver, iPhone Dock, Roku, receivers for Lenovo remote and Logitech Keyboard

Right side of the TV: receiver for mouse, heavy rain oragami, 8 port gigabit switch

My NAS, it's named ASGARD