7,000 for me - plus handicap that drives the ball about 265 in normal conditions. I can get it out there 290-300 on a slightly firm course if I'm really playing well.
More important than total yardage is a course with a mix of lengths in the holes. I played Bandon Dunes at 6,900 but not one par 5 was reachable for me. It is really rare I play a course where I can't reach at least one par five in two. The other problem with 7,000 yard courses is that almost every par 3 ends up between 180-210 yards. So, I hit between a 3 and 5 iron on every one - which is extremely boring. There really are very few courses that are set up where you will hit every iron in the bag during a round. Years ago when Pinehurst #2 had 3 sets of tees and the back tees were 7,000 yards or so it was one of those courses. Now that they've added length for the Open I either have to it at 7,300 yards - too long, usually hitting 3 or 4 iron into every par 4 and a couple of 3 woods into some - or 6,700 yards which is too short and results in a lot of short, medium irons.