Correct order of boiling points of hydrogen halides is

The boiling points of hydrogen halides generally increase with increasing atomic/molecular size and increasing intermolecular forces. 

The correct order of boiling points of hydrogen halides is: HCl < HBr < HI <HF

HF has the highest boiling point due to the strong hydrogen bonding between HF molecules. The H-F bond is highly polar, and as a result, hydrogen bonding is particularly strong between HF molecules.