I really love my Continental Travel Contact tires. Plenty of smooth surface to hit the road but there is something there to dig into gravel, or if you get forced off the road into sketchy stuff. My Gunnar has 26 inch wheels so I've the mtb version, but the 700C has the same tread pattern. Very durable, I've several thousand miles in these tires now and there is a lot of life still left in them. Not one flat so far (knock on wood).

These are pretty wide (either 26/1.75 or 700C/37) so your fork might not take them but it is worth checking. Rides like a dream, very smooth.