+1 HDMI is the way to go
It will offer you the best quality picture and sound possible - plus it is relatively easy to connect and set up with a PC.
If your PC only has DVI outputs, then use an adapter like
this or a cable like
this (if 3m is long enough).
If you do buy a HDMI cable (standard male-male is what you need) then make sure you don't spend more than £15. There are LOADS of very expensive HDMI cables that promise the earth and cost a lot of money - for lengths of under 5m these cables offer image and sound quality that is identical to cheapest cables you can buy for a few quid.
This cable is a good option (and you get free delivery).