Which antipsychotic medication has the lowest risk of Tardive Dyskinesia as a side effect?

Answer 1

The atypical neuroleptic clozapine (trade name Clozaril) has very low incidence of extrapyramidal symptoms and TOTAL lack of tardive dyskinesia, though it is not commonly used.

Answer 2

While citizen insane is correct, about no document cases being direclty attibutable to Clozaril, Novartis has published a report noting that there are reported cases of tardive dyskinesia developing while people were taking Clozaril _after_ switching from a different antipsychotic. They also note that there is still a theoretical chance of developing TD.

Also please note that Clozaril still has a list of side effects and adverse reactions including agranulocytosis, seizure, cardiomyopathy, etc (see the reference) that should also be taken into consideration when starting or switching a medication.