This is an interesting discussion -- I'd submit that domestically in the States that the new Dye course at Pound Ridge in NY would have to be one of the leading contenders. Just brutal.
On the foreign side of things -- play Dunluce at Portrush with any significant wind and if the fairways are kept narrow with hay-like grass flanking the short grass -- then it's likely you will need no less than a dozen balls to complete the round and should you experience a military type round (left / right / left) then all bets are off.
Matty
"..you will need no less than a dozen balls..."
Does everything need to be blown out of size for you to get the point across? I agree the rough is a major drawback of Portrush and will probably keep me from ever returning. But it shouldn't take anything like 12 balls to get around. We had a guy in our party whos cap is so high he can't have a cap. It was tough for him, but I think it was only a two sleeve day.
Muirfield is also very harsh, but its fairways don't snake nearly as much as Portrush's and I think the fairways are probably wider.
Another too high to have a cap mate of mine had a rough time at Co Down - I think he lost close to 15 balls. I didn't think it was that bad, but still not a pleasant experience being in the rough.
Lets face it, in high season practically all links have issues with rough. Its a shame that high season coincides with the peak tourist time of June through July/August. I think this is why fairways used to be so much wider - to accommodate the summer growth which combined with the odd bad wind day can make a course a waste of time to play. Now, for championship links, add in all the bunkers which have narrowed courses even further and its a recipe for what we have been experiencing for the last decade or so. Now add in the effects of in-expertly applied artificial watering and its easy to see how we got to where we are today. Bring back the width, cut the water, and things would be much better.
The one big name course which I think stands out from the crowd as consistently keeping its rough down is North Berwick. I know many poo poo the course as too easy and having a handful of uninteresting holes (I disagree with this sentiment), but I think the playability of the course is endearing as the funk and a reason many love the course.
Ciao