First thing is - the VGA input on your LCDTV will only accept an analogue signal, so there's no point getting an expensive DVI-VGA lead since your graphics card will just detect it's connected to an analogue display and output an analogue picture through it's DVI output (it would still work of course, it just wouldn't gain you anything). You may just as well get a regular VGA lead and connect VGA to VGA. Just make sure it's rated up to the resolution you intend to use since the cheaper cables get blurry at high resolution.
In fact your video card probably came with a DVI-VGA adaptor, if you need the VGA output on your graphics card free for another analogue display.
The DVI-HDMI option does give a digital tranmission of the picture, so you're guaranteed the best picture quality, but in reality you probably won't see a difference between analogue and digital, and the cables are rather pricey.
I would just go with a VGA cable, assuming the LCDTV does indeed have a VGA input.
Be warned your PC won't support a resolution like 1366x768 without a little work. I believe you have to use powerstrip to make a custom resolution and even then some games may not support it. You might find you have to use something like 1280*768 in some games.