The best option is the NJ transit bus. You'll drive to the Exit 120 Garden State Parkway Park and Rice and get on the 135 bus to Port Authority bus terminal in Mid-Town. It's a 55 minute trip and costs $278/month.
You could also take the train from Middletown station to NY Penn Station. There are no transfers needed and it's about a 75 minute trip.
If you want to learn more about what each of the towns in Monmouth County have to offer and where they lie in relation to mass transit, check out the map and Buyers Guide I've created (link below).
Please let me know how my team and I can further help you.