The above are good information. Your stated needs are too ambiguous to offer very specific information.
Basically, if the cable experience of having ready access to lots of channels of programming is important to you- including live programming like news and sports- you need to pay up for that box and/or switch to someone with a similar offering (DirecTV or DISH or Canada equivalents?).
If you live near a city, consider putting up an antenna for the major networks "over the air". If you live even closer, even old "rabbit ears" might be able to get you the majors for free. Dig them up and try them on the TV (need an HDTV tuner to see if it works or not).
If your computer screen needs to become your TV screen, consider a USB TV tuner like those offered by Elgato. This can work with the antenna setup as well as cable if it is decrypted channels (which are usually the major networks and sometimes a small selection of others). You may find that canceling cable but leaving it hooked up will keep some core channels available- even more likely if you maintain a broadband internet relationship with the cable company.

TV3 has no jailbreak. Going that way means paying for each episode of what you want via whatever you can get from iTunes... and/or subscribing for other content to stream from sources like Netflix (which you can probably get in Canada) and maybe Hulu Plus (do you get that in Canada?). Look over their offerings to see if that could be enough for you (again, local news, live programming and live sports are the big miss for many cable "cord cutters"). If you are a frequent channel surfer,

TV3 offers you very little for just hunting around for something you want to watch for one flat fee per month.

TV3 is not a cable box replacement (unless the above can satisfy you). If you are going to go for it with Netflix and/or Hulu, you don't need

TV for those- just use the computer.
The biggie is those live locals, live events, live sports. If any of that matters to you, you pretty much need to go with cable or satt unless you can get that from the majors via an "over the air" antenna plus an Elgato-like tuner hooked to your computer. If the hangup is paying for a cable box, the satt companies usually give away the equipment for new subscribers and their pricing can be as good- if not better than- local cable- especially during "initial promotional periods".