You could go with a wider touring tire that is mostly slick but has more puncture resistance.
Another option would be something like these two Clement lines. I have friends with these tires, and have done gravel and road surfaces with them and raved about the tires. Apparently a bit pricey and hard to get though.
http://clementcycling.com/ush
http://clementcycling.com/xplor-mso
For a file tread - my CX bike has Ritchey tires:
http://www.ritcheylogic.com/dyn_prodfamily.php?k=98784 and these are fine for light offroad but I don't corner hard on the road on them.