Day trip. North end is tight, the rest is very nice. Because it's next to the M1 you can normally get good stretches without traffic. Lots of hoons on there that can lead to some fun... Old Road Cafe and Pie in the Sky for stops, Pie in the sky is better.
Weekend trip. Gerroa, Berry, Kiama (little blow hole), Kangaroo Valley, Robertson (Robertson Public House) are all worth a look. Excellent road but VERY likely to have traffic. Pretty tight. They are separate roads but are so close that it makes sense to do them together. Best to start at the bottom, near the coast. Myra Vale Road/Pearsons Lane is a good shortcut between Moss Vale Road and Macquarie Pass.
Multi day trip. Walcha, Gloucester, coast (Moorland Cottage) very good. Incredible road. It tires you with persistent glory. Never had traffic problems.
Day trip but also works well as part of South Coast trip with Macquarie Pass etc. Good mix of tight and flowing. Fairly likely to encounter traffic. Scarborough Hotel gets very busy but worth trying, sit outside.
Weekend trip. Colo river good for camping and swimming. Good road for motorbikes, boring in car except for north end. Likely to get traffic.
Weekend Trip. Newcastle, Foster area good. Insane road. Never any traffic.
Multi day trip. Yackandandah, Albury, Bright, Beechworth (Brewery), Rutherglen (Parker Pies) all good. Brilliant road, we've never had too much trouble with traffic but I assume it gets bad at certain times of year (snow season?).