Whats the best offset for a set of 16 inch rims for a 98 integra?

 

Stock 6" wheel is +45 mm I believe. Offset changes with wheel width not diameter. Also there is no "correct" answer, although obviously closer to stock is generally better and dramatically different offset won't fit.

 

Without modifying the car to increase wheel/tire clearance, the lowest offset you could go with safe tire sizing would be a 16x7 +35. Remember that offset is a measurement from the center of the wheel, and without knowing the wheel's width, the offset is entirely irrelevant.