When I lived in Colorado the smart move in Denver was to start lining up about an hour before the DMV opened (for driver licenses, car registration never had much of a line). Out in the mountains, I was able to just walk in just about anytime. The longest wait I had in the small mountain town I lived in was when the one lady working there was doing a driving test, and I had to wait 10 minutes for her to get back.
Living in Washington, they allow private businesses to register vehicles, so transferring a car was normally a 5 minute job. Never did bother to switch my DL, so can't comment on that.
Now I'm up in BC where vehicle and driver licensing is handled by the state owned insurance monopoly. Any agent, private or public, can register your car. You can get the licensing done at public insurance offices, or at provincial service centres that handle all sorts of business by appointment or walk in. It all works pretty well.