The absolute nicest tires I have ever tried in 700c were the Clement X'Plor MSO in 35mm width. The had the plushness that I desired and they rode well on pavement. On gravel they excelled.

For flat protection I used Schwalbe Marathon Supremes. The rode like rocks, I feel like I am in the Flinstones, but you will almost never flat. Horrible riding tires but you know you are going to get to work if that is your gig.

I have been riding Gran Bois Hetres for the last year and you can get the same casings in 700 (also Compass tires) but finally gave up because of the number of flats in the city. Too many pieces of glass and little wires work their way through. But again the ride is 10 out of 10. Now I am back to Marathon's that ride like rocks but almost never flat. I guess I like extremes.