And cheaply, and if so, what all would I need, besides a computer and a TV?
All you need is a video card with some sort of TV-OUT, like an S-Video jack, on it, and some way to get the sound from the sound card to an Audio-IN jack on the TV or sound unit you have.
ETA, and with the advent of HDTV, you might be able to use the DVI output of a video card directly to an HDTV. I have DVI-OUT, but no HDTV. Still have to deal with the sound.
By video card, do you mean something that needs to be installed inside the computer?
Yep. However, you may already have a card with this capability in your computer. TV outs are pretty common these days. What sort of computer do you have?
Your computer might have onboard video, where the “video card” is built on the motherboard. If that’s the case, then you might not (probably not) have TV-OUT capabilities. I’ve never had an onboard video motherboard, not sure what the norm is for that. This rig at work has a video card with R-G-B outputs (component video), as well as the regular ol’ VGA monitor plug. At home, it has DVI and S-Video. My TV has an S-video IN, some TVs might have component video IN (I don’t think mine does)
Might want to back up and list what system specs you can, for the computer and TV.
Whatever Dell’s cheapest non lapop is- a 2400 I think. As for TV’s, I have several I could use, all under five years old but none HD or LCD or plasma or anything- not sure of any models or brand.
We need more detailed specs than that, given how configurable Dells are. At least a more specific model and number.
In general, I would guess that the absolute cheapest Dell desktop wouldn’t have such an output, but one of the modestly upgraded versions would.
Definitely a Dell 2400.
Then no, you cannot do this without getting a new video card. The Dimension 2400 comes standard with onboard video, which does not include SVIDEO out.
I doubt even a new card would help. I don’t think the 2400 has an AGP or PCI-E slot. I suppose a PC video card would work, but blech. 
You could go another route… burn the videos to CD or DVD and play the discs in your DVD player, instead of hooking the TV to the computer.
Assuming you have at least a CD burner in the laptop and already have a DVD player hooked up to the TV, that’d be the cheapest and easiest way to go.
bouv is right - you can’t even upgrade the Dell to do what you want.
However, there’s external products like these you can purchase at your own risk.
I guess this would be a perfect time to get a better computer- It doesn’t have a DVD burner either 
Thanks all, and one last thing- assuming they exist, can you buy an external DVD burner that would be compatible?
They do exist, and it’d undoubtedly be compatible. I’d suggest just getting a regular dvd burner to put inside your computer. Worst case scenario if you have some odd case, it would just replace your old CD drive. This would be more reliable, and probably cheaper even if it meant you had to pay someone to install it for you, should only take them 10min or so to put it in.
A DVD burner is not needed, just a CD burner. You can burn a VCD or SVCD (Video compact disc or Super-video compact disc). You will need software to do this. Most modern day CD burning software should have the ability.
I rarely want to play video from my computer on my TV, but when I do I’m using my laptop with a mini-DVI out. I have a mini-DVI to VGA adapter which I then plug into the VGA input on my TV. (I could do the same in effect by mini-DVI to DVI to HDMI, but that’s way too much work for no benefit.)
Of course, your TV may not have a VGA input. But if it does, you can just the TV as a monitor.
If the videos are in mpeg-2 and you have a Tivo, you can view them over your home network using a free download called Tivo Desktop.