I know of a couple in the Simsbury/Granby/New Hartford areas. I'll give you rough directions but make sure to scout them out first with mapquest, or google maps.
Simsbury - to - Ski Sundown
1. Start out on route 309 heading west. You will head up into the hills hitting some nice twisty's along the way.
2. Turn left onto route 179 (Cherry Brook Rd) and it's a nice straight blast for less than a mile.
3. Turn right onto Wright Rd., this turn comes up fast if you are going real quick. This is a long twisty section of back roads; narrow, hilly, and twisty. This is the meat of this run.
4. Turn left onto Ratlum and you will come down to Ski Sundown shortly after that.
Optional - At this point you can continue on Ratlum down to route 219, make a right and follow the road that goes around the reservoir. It's another nice little section of twisty, and blind corners.
Firetown Road, Simsbury
This is an easy short one with a nice section towards the end.
1. Start at the intersection of west street and route 10, and head west on West St.
2. Make the first right onto Firetown road at the stop light.
3. Follow Firetown road all the way to the end. The first few miles are all residential so you have to watch your speed but once you pass Old Farms Rd the population thins out and you can open it up as you blast through the woods all the way to the end, at Simsbury Rd.
4. At the stop sign, you can either make a right and head back to route 10, or you can go left and head North into Granby and then go west towards the Barkhamsted reservoir.
Albany Turnpike - NW CT
Someone posted in another thread that it's a great drive heading up to Limerock Park, and it is. Another way to get up to that corner of CT is to take the Albany Turnpike (route 44). It's a long trip, because of all the stop and go along the way, but there are some great sections of road on your way up to route 7. Just bring plenty of CDs because you will start to loose the radio stations as you get away from Hartford.
Anyways, hope that helps have fun. And I feel the need to say it, be careful because these are public roads yada yada yada. Kids are worth double points.