Is it safe and secure to use client side cookies for "logged-in" session as opposed to server side sessions?

Try to consider what are you going to store in the cookie, say if you want to store user name to access next page then hacker soon will know what to set in his cookie to access someone else page. If you set a random number or text then your server need to know to recognize it. Which is eventually is session. If you think of storing password encrypted or not, you are screwed. World has moved from cookies to session. So, make your choice:)