I'm liking the G-One Allround in 40c for road and light gravel if I could only pick one tire. I was running the Terra Speeds, but seem to prefer the Allrounds - not sure why, though. The Allrounds are slightly larger volume by 1 or 2 mm. Both are very similar and can't go wrong with either.
I also have Barlow Pass's on another set of wheels in Extralight casing. I run them tubeless and have about 1500 miles on them, about half on dirt/gravel and the other half on pavement. They did weep slightly on initial setup with Orange Seal Endurance but set up fine after another day of riding and another ounce or so of sealant. They ride differently than anything else and sort of like a nice quality tubular.