Cheapest way to show HD videos on my TV from my desktop: HDMI or DVI PC output?

[any ANONYMOUS forum user]

My 55in LED LCD TV that I just got and picture looks good playing 1080p movies with my pc using vga but I know it could look better. I was reading that DVI can do HD video but I guess not 1080p so then I should be looking for a HDMI card? That seems cheaper.

I am looking for the cheapest way to be able to playback 1080p HD video on my HDTV with my PC. Currently I have the VGA cable connected but would like to upgrade to either HDMI or DVI. My PC has a nVidia GeForce 6150se nforce 430 video card which doesn't have either currently. I've been looking around for PCI video cards but everything seems kinda expensive. Does anyone know if my video card supports ADD2 or if there is a cheaper alternative to getting HD video to my HDTV from my PC?