This isn't as straight forward as some might think.
Generally speaking neither VGA or DVI will output audio so you'll need an audio cable as well as a video cable so taking that in to account VGA would be the easier option as the TV will have the correct audio input to go with the VGA input (HDMI inputs won't have a separate audio input to go with them)
However..... Some ATI graphics cards can output audio through the DVI connector in a non-standard way which can then be used to combine the video and audio in a HDMI cable, but only if the special DVI - HDMI adaptor supplied with the card is used.
So....
If you have an ATI graphics card that supports audio out on the DVI and you use the correct adaptor then DVI - HDMI - TV will work and give you video and audio.
If you don't have a ATI card that supports audio on the DVI then VGA is your only option if you want sound through the TV as well as video. (but you'll need a separate audio cable)