What're the least drowsy sleeping pills available?

I am not sure what you are asking. Sleeping pills are designed to make you drowsy so that you can fall asleep faster. Or, do you mean they have lesser effects in the morning?

Yea. I meant like to take them to help me sleep but I don't want a bloody hangover from them. I know some pills cause this and I don't need it. I just need to get over my insomnia for a few hours.

You may choose to take meds which has chlorphenamine. It can mke you feel drowsy and can really put you to sleep. If I want to sleep but cannot easily do, I take a decongestant and it gives me the effect I want over night.