Warning: A lot of information/options/ideas. I make a recommendation at the bottom.
Thank you. Here are some pictures of the connections available on my Toshiba Regza.
Link: Toshiba 42LZ196 42" Cinema Series Pro high-definition 1080p LCD TV at Crutchfield.com
So you're saying the best way is DVI>PC monitor, and HDMI>TV, correct? If so I'll go grab a 25 foot HDMI cable. The next issue will be is my PC capable of sending an audio signal via the HDMI cable, or will I have to run separate audio cable from the PC to the TV as well? You can see my existing audio outputs on my PC in the pic on the first page. The green plug goes to my Logitech desktop speakers.
In terms of the PC to the monitor, the best way would be DP* > PC, but in your current setup, I believe the DVI > PC is the best, yes.
Here's a couple of options for your consideration, now that I've seen the TV's connections:
Option 1: TV-controlled input selection
input i: From PC via DVI to DB-15 converter (not ideal)
input ii: Either the Rogers box or the Xbox
input iii: If (ii) is the Rogers box, then this is the Xbox. If (ii) is the Xbox, then this is the Rogers box.
Option 2: TV and HDMI switcher input selection
input i: Either the HDMI switcher or one input source of your choice.
input ii: If the HDMI switcher has enough input ports, than this input source may not be needed; consider this input to be a type of 'overflow' if you have more HDMI sources than the HDMI switcher provides.
Another option (I don't have a quick picture) you might consider, if the Rogers box (I'm assuming that's the cable box) offers the connection, is to connect it via the Cable input (to the left of HDMI 1, when facing the TV connections). This would 'free' the two HDMI sources to be the PC and Xbox.
If your TV service supports it (ask them), you might be able to skip the Rogers box completely and connect it from the wall to the TV at the cable port (you may need to read some documentation on this, but some TVs can perform the selection of TV channels, usually called the 'TV tuner').
The one thing I like about these kind of questions is that there are many options to choose from. If you're serious about the TV becoming a central fixture (movies, shows, et cetera... but we know you want the big screen prawn), then I'd suggest throwing in an HDMI-capable A/V receiver setup. This will allow you to handle the HDMI sourcing a little easier (it seems you need a 3-in/1-out setup, at the minimum). A side benefit is that you only have one HDMI connection to the TV, as everything plugs into the receiver, which then controls the input selection (the video is 'passed through' to the TV, while the audio is intercepted and played through the speakers).
For example, here's a 4-to-1 HDMI In/Out setup (with speakers)
The 'problem' with this approach is more wires, which can get a bit confusing, as well as needing to turn on 2 (or 3 devices, if the computer is off) before enjoying your content. The cool thing is, the receiver is pretty much a one-time setup. After the initial setup, 'it just works', after getting used to the new way of doing things (turn on TV, turn on receiver, select input source, go).
hmm: Newegg has the manual for the model number.
Ah, another option: Have a dedicated computer for the TV, what is known as an HTPC ("home theater PC"). The main function of these computers is to access and display your content. Here's an example HTPC
(by no means the best), but if you have some spare parts laying about, you can also build your own HTPC.
*(DisplayPort, a newer connector type, but hasn't really 'gone mainstream' enough to become saturated as part of many home setups...)
Recommendation: The A/V setup I linked to makes a compelling option, in my opinion, and for simplicity, I would suggest getting that, as it has plenty of inputs for what I see you're currently using, plus a few options for adding more devices later (like a PS4). I would also recommend getting an HTPC, as that will segregate user concerns (PC-centric usage/TV-centric usage), but that might the next "upgrade" for centralizing your entertainment area.