These cables like to get really stiff in cold weather...is it better after the car has been driven? Usually is, if the cable is the problem.
If not, and it's a console shift, take the above poster's advice. I've seen a little bit of coffee and sugar residue keep a 200 pound man from being able to take it outta park, once it dries up in there enough...
Surprisingly, the majority of the sticky is from the slider window with the pointer on it...even a shot of WD-40 on the PRNDL window will usually make a big difference in these cases...
At any rate, if the cable is the problem, as it was with mine, I simply separated it at the junction under the hood by the airbox and shot oil into the sheath...it softened up the dried grease, works fine now...