IMO, I like Harrahs in the Marina district. It feels safer than at the boardwalk casinos. The waterfront or bayview towers are newer rooms, but the atrium suites are ok too. If you are young enough, the Pool nightclub is also a plus. You could walk to Borgata (10 minutes tops), but it is a $13 cab ride to the boardwalk. There are free (I believe) shuttles to other Caesars boardwalk properties if you don't mind the wait.
That being said, you must visit the boardwalk and walk between casinos (weather permitting in the winter). Keep an eye on your wallet/purse. I witnessed broad daylight snatch and run robbery on a Sunday morning last summer.
I always fly into Philly vs Newark. It is 1 hour vs 1.5 hour drive, and rental cars are cheaper out of Philly.