TV out is not arcade perfect because the interlacing offsets the scanlines between the odd and even fields so that the image will be jumping up and down at 25 or 30 times a second. If you drive an old analog TV with arcade timings then the lack of interlace will make it arcade perfect, but the tv encoder on a video card will never do that since its not a valid ntsc/pal signal when that happens.
I tried composite and svideo and it either was blurry, or if I turned the flicker filter off it was jumping up and down at 25/30 FPS.
If you can get 480P out then it will not jump up and down but will have twice the number of scanlines, so you need to play with the effects to get the blank lines inbetween the ones that are from the game. I had it looking pretty good, but I couldnt find a 480p capable 4:3 CRT tv to put in my cabinet. Looks great on my normal tv if you accept that there is 3" of unused screen on either side since its a wide crt.
The other option is a VGA to component converter and use arcade timings on the vga output. That worked for my mate when we built his cab, tv shows a double image during bios etc, but settles down when in the front end with arcade timing. It was an old analog tv however, I havent tried that on a digital display.