I picked up a Trek Verve a few months ago because my family needed more bikes. It came with some Bontrager H5 tires. They seem like cheapo tires. They worked well for the first 1000 miles or so. We did some multi-day bike tours with it, and it gets ridden around town, to the gym, to church, library, to get groceries, to 4-H club meetings and for recreational bike rides on the MUP. Lately, it's suffered three flats from goatheads. I'd kind of like to upgrade the tires, but it also seems a bit frivolous.

So the Verve has 700Cx45 Bontrager H5. I have another bike with 50mm Schwalbe Big Ben Plus. These tires seem to be a lot tougher and the ride is luxurious. Should I get a set of Big Ben Plus in 700x50 for the Verve?

What other model tires might be a better choice?

I'm pretty sure I'd want 50's. I don't really need the aggressive tread of the Big Ben. Big Apple's tread would be fine but they're rated by Schwalbe two steps lower on puncture resistance. I like Contis too, but I don't have anything but the road tires (GP5000, US3).

What's a good non-knobby ~50mm tire?

If I don't get something significantly better than the H5, I'm just wasting my time and money. On the other hand, some of the more expensive tires will cost more than half what the bike is worth. I'm ok with that.