I have a MTB setup more or less as an urban cruiser. I just put Continental Town and Country tires on it and so far I think they are great. At 1.9" they are wider than the OP was originally considering, but they make for a comfy ride.
I have a hybrid with CST (Chin Shen Tires) on it that have also worked out well - better than I expected. They make several commuter/street versions Selecta, Salva etc which have some tread but no knobs. Most the 26" MTB flavors are 1.75" so a bit less than typical MTB without being road bike slim.
One to avoid: Michelin City Tires - not durable at all