Twisty? Smoothest pavement? Best scenery? Best rest stop bathrooms? Best Hitchhikers?
Depending on where you are in CT. The roads south west of Bear Mountain State Park has a lot of excellent twisty roads with great pavement. (Arden valley road, Kanawauke road are my favorites) and highway 202 isnt bad either (lots of traffic)
My favorite is just taking a day, driving up through Litchfield County and getting completely lost (as much as one can get lost in CT). Basically right where ConBroMitch suggested. I usually just tool around through Kent, Warren, Cornwall. No destination in mind, just taking random back roads. Sometimes I shoot for a lake or a state park so I can get out and stretch my legs a bit. It's a leisurely drive, twisty roads, awesome scenery.