Tel Aviv is the most coolest party city. It is a place which everyone would love to visit if they simply google search about it. Have had a lot of friends who have been there. It is super expensive and super safe. They have underground parties too. My friend literally broke a tap to enter the nightclub and that is something I've only seen in films. Definitely worth a visit if you're a party person. The Jerusalem area is not that safe but its a short trip from Tel Aviv. If you go to Israel, your visa from a lot of other countries will be rejected in the future, keep that in mind.