If you deem it as the safest course of action by all means. I have landed at ORD without a clearance. If you don't have a landing clearance at ORD it's probably because they are tied up with the aircraft that is going around.

UAL used to teach an initial Captains course and this was one of the questions that they asked - You can't get a word in on the radio because ATC is busy with... You can see the runway is clear. Do you land or go around? The answer that they, and ATC wanted to hear was land.