I give them all a visit from time to time, but not as frequently as I used to.
Conrod's pretty quiet these days, since the purges,
10-10th's has its uses, although nobody there knows half as much as they think they do... Central's a bundle of fun, there are some good folk there... but more than the average collection of idiots. Still, if you're careful, you can bucket those who need it without too much hassle from the mod's (just got to choose your wording carefully)... I've had a couple of yellow cards there, but they were earned, and I expected them, and welcomed them as the price to be paid for saying what needed saying at the time.
I joined V8Nation just to see what the big deal was, and it's pure vanilla; everybody agrees that Rick's a legend, Skaife's a legend, and there are a couple of fairly scary birds there talking about tatooing drivers' names in places that should never have writing... and should never be read for good measure...
I troll the brockcommodores site to glean what knowledge I can there, and similarly with the Nostaliga Forums at Atlas F1, which is a goldmine if you're big on motorsport history - particularly F1 and sportscars, although you get some other categories mentioned. There's a strong Oz contingent, including journo's, and there are driver members (who you don't see much of, but who include Brian Redman, Vic Elford and Kevin Bartlett among them). If you want a laugh at first-hand experience get over there and do a search for posts by Buford - he grew up at racetracks like the Brickyard, and has a great perspective on motorsport. Anyone who has read Doug Nye's work will love the joint.
Now, for all that, THIS is the definitive DJR site in my mind - I haven't been near the whole "official" site in donkeys', as the corporatisation of motorsport offends me a bit. And it's thanks to the hard work of the mods that it is what it is.