HD DVD would probably have won, 360 would probably be in third place (assuming PS3 launched much cheaper without BR).
I think the Wii wouldn't have sold quite as well but it's of course hard to be sure. I still think it would be in 1st place, but with less sales, with PS3 not too far behind and 360 a fair way behind.
the recent 360 price attractiveness is based on how well the console managed to sell with PS3 out, but I believe it would have seen a big, immediate drop if PS3 had been much cheaper with DVD drive only.
Try to be reasonable... its easier than you think...