Great Driving Roads and Location In/ Around Sydney

Old Pacific Highway, AKA 'Old Pac':
The good part of the road starts just north of Berowra and it ends around Somersby. It runs adjacent to the F3/M1 freeway, crossing over or under it at various points. On a good day (when there is minimal traffic/cyclists and no HWP), this is one of the most enjoyable roads of all. 
https://maps.google.com.au/maps?saddr=Pacific+Hwy%2FB83&daddr=Pacific+Hwy%2FB83+to:Pacific+Hwy%2FB83+to:Pacific+Hwy%2FB83+to:Pacific+Hwy%2FB83+to:Pacific+Hwy%2FB83+to:Pacific+Hwy%2FB83+to:Pacific+Hwy%2FB83&hl=en&sll=-33.438497,151.250968&sspn=0.02582,0.054717&geocode=FVwf__0do38CCQ%3BFahv__0d9LACCQ%3BFe9AAP4d4R4DCQ%3BFX2zAP4dXf4CCQ%3BFVRwAf4d2AIDCQ%3BFYTgAf4dkowDCQ%3BFVTjAf4dxpwDCQ%3BFcQQAv4dQngECQ&mra=ls&t=m&z=12
 
Galston Gorge:
This has a bunch of super tight hairpins, so it's only fun when there's no one else around. It's only short, but it can be combined with an Old Pac run (see above). 
https://www.google.com.au/maps/dir/-33.6801752,151.0979003/-33.6621756,151.0839983/-33.6561706,151.0677177/@-33.6640981,151.0648428,14.25z/data=!4m2!4m1!3e0
 
Royal National Park, AKA 'RNP' or Natio/Nasho:
If you don't get stuck behind traffic then this one is really fun. There are some good/safe overtaking areas before the best part of the road anyway. This road begins as Farnell Avenue near Loftus. Most people stop at Stanwell Tops before turning back, but if you're willing to drive further south then there is a beautiful seaside drive to be enjoyed. 
https://maps.google.com.au/maps?saddr=Farnell+Ave&daddr=Sir+Bertram+Stevens+Drive+to:Sir+Bertram+Stevens+Drive+to:Lady+Wakehurst+Drive&hl=en&sll=-34.208111,151.015406&sspn=0.025589,0.054717&geocode=FWBc-P0dc9AACQ%3BFS0S-P0dkfMACQ%3BFcTj9v0deoQACQ%3BFW0A9v0dfUAACQ&mra=ls&t=m&z=12
 
McCarrs Creek Road:
Turn off Mona Vale Road and away you go. It's a great drive when there aren't too many cyclists in the way (night time can be better for this reason).
https://maps.google.com.au/maps?saddr=McCarrs+Creek+Rd&daddr=McCarrs+Creek+Rd+to:Pittwater+Rd&hl=en&ll=-33.663568,151.267061&spn=0.051506,0.109434&sll=-33.667854,151.281395&sspn=0.051504,0.109434&geocode=FUYM_v0d45kDCQ%3BFYdv_v0dSjQECQ%3BFUQp_v0d-7MECQ&mra=ls&t=m&z=14

Bobbin Head Road / Ku-Ring-Gai Chase Road:
Much the same story as McCarrs Creek Road (and they are also quite close to each other, if you want to do both).
https://maps.google.com.au/maps?saddr=Ku-Ring-Gai+Chase+Rd&daddr=Ku-Ring-Gai+Chase+Rd+to:Bobbin+Head+Rd&hl=en&ll=-33.670926,151.141663&spn=0.051502,0.109434&sll=-33.67664,151.134968&sspn=0.051499,0.109434&geocode=FdgZ_v0dXPABCQ%3BFThm_v0dQYACCQ%3BFYP0_f0dhmcCCQ&mra=ls&t=m&z=14
 
Springwood Rd / Mitchells Pass / Old Bathurst Rd:
Turn onto Castlereagh Rd starting at either Richmond or Penrith, then turn onto Springwood Rd.  Follow Springwood Rd uphill until you get to the Hawkesbury Lookout, where I recommend that you stop for a look at the view. Then continue until you reach the Great Western Highway, and turn left. Turn left onto Wilson Way and follow it until the roundabout where you turn left onto Mitchells Pass. Follow Mitchells Pass until the end, then turn left onto Russell St and continue along Russell St until Old Bathurst Rd, then turn left. Follow Old Bathurst Rd uphill until you reach the end (note: at the top there's a United servo with E85). 


Those are the closest options in Sydney, but if you're happy to do a longer drive then continue reading...
 
 
Putty Road:
It's a very long drive, but a really good one. There are multiple sections of fun and varying corners, separated by some straight stretches of road, but the best part of the drive is near the northern end just before Milbrodale, with almost 20km of non-stop awesome corners. 
When you reach the northern end of Putty Rd, if you don't want to do it all over again in reverse, then you may want to turn right at Milbrodale Rd towards Broke, then turn right onto Wollombi Rd, and drive all the way to Somersby. From there, you can have even more fun by going south down Old Pac, or you can jump on the F3/M1 motorway back to Sydney. 
https://maps.google.com.au/maps?saddr=Wilberforce+Rd&daddr=Putty+Rd+to:Putty+Rd&hl=en&sll=-33.114549,151.22406&sspn=1.955355,3.56781&geocode=FepX__0d2n39CA%3BFdAvBv4dek77CA%3BFQcfDf4dzwoACQ&mra=ls&t=m&z=10
 
Macquarie Pass:
It's pretty far from Sydney, and it's only a short run, but it's so much fun you'll probably want to go up and down the mountain multiple times! You can also choose to drive down Jamberoo Mountain Rd from the top of Macquarie Pass, and/or head over to Kangaroo Valley which is also nearby. 
https://maps.google.com.au/maps?saddr=Illawarra+Hwy%2FA48&daddr=Illawarra+Hwy%2FA48&hl=en&ll=-34.571249,150.654831&spn=0.050957,0.109434&sll=-34.571234,150.661195&sspn=0.050957,0.109434&geocode=FYRt8P0do0r7CA%3BFVlB8P0dtF76CA&mra=ls&t=m&z=14
 
Bells Line of Road:
This goes out to Lithgow. It's quite a long drive, but certainly a fun one when there isn't too much traffic. 
https://www.google.com.au/maps/dir/-33.572876,150.7122798/-33.541379,150.422268/-33.4728732,150.1809421/@-33.5827481,150.401997,10.5z/data=!4m2!4m1!3e0?hl=en
 
 
Happy driving!

+1 for Macquarie Pass.
I did it last year in a hire Mercedes motor home on a Sunday going to Kiama.
Met one group of Lambos & Ferraris & one group of WRX's coming the other way before we got to Macquarie Pass & then knew why.

Do Old Pac next if you haven't already. Otherwise McCarrs Creek or Bobbin Head Rd.

I grew up 10mins drive away from mac pass, so know it like the back of my hand. They've done great work on it in the last few years, but it's still a road you need to err on the side of caution; it's not a well planned japanese touge, it's an old horse and cart track that twists and turns and has a lot of sections you could come to grief.
I find it a lot more fun on the uphill than the downhill, because you have a better perception of braking points before attacking corners. The Autodub has a score to settle with that road.
 
Indeed Mount Keira road was a lot better, but the spandex parade frequents there too, and yep the road is closed indefinitely at the moment.

Dudeman already stickied it. I assume you guys can move it to the NSW section?
I didn't even start this thread initially.

Old Pacific Highway is, in my opinion, hands down the best road in Sydney!!! As a motorbike rider as well I have spent many a day and night there 
 
I live in Mona Vale so have been doing McCarrs Creek Rd regularly my whole driving life, great road, been recently re-tarred. Just do it at an irregular time like night to avoid the cyclists. 
 
And finally I've done Putty Rd loop (Wilberforce - Broke - Wollombi - Old Pac) which takes about 7 hours, twice on my bike and it is about as good as it gets if you want to do a whole day trip and see some country side.
 
Natio was pretty good but it's just too far away from where I live, and when I did it I had a Forester in front of me doing 50 km/h :(