700x40 Michelin Protek Cross Max, heavy duty puncture resistant tires with a chevron pattern tread that's a good compromise for paved roads and unpaved trails, grass, etc. Heavy at 1,110 grams, but my bike is heavy and I'm slow so it suits my preferences. I don't do any stunts and average only 12 mph regardless of the bike so my priority is a stable ride and not falling down when I venture off road.
I tried a Trek 7.5 fx a few months ago and while I liked the bike pretty well I didn't care for the skinny road oriented tires. First thing I'd do is put on something a bit wider with a bit more grip to handle the mixed terrain I like to ride.