There is no bus from the cruise line. We did the Spirit last year; we also live in CT. For us, it was easy. My husband dropped us off as it was only the kids and I going.
If you can handle it, MetroNorth followed by a taxi is a choice as LisaP suggested. However, when you figure out how much that costs (the train isn't cheap anymore!)for all the segments it's probably just as easy to call a local limo service and have them take you. You'll still have to park somewhere to get on a train and then handle the baggage on a train, in a taxi, and so on. Limo = door to door service. Splurge a bit and keep your car safe at home too.
I know that when my ex-husband and I went on a cruise out of New York, when I was still living in CT we ended up driving. I'm almost sure I checked out all other transportation options and ended up just driving there.
09/07 CCL Fascination
03/07 RCI Voyager of the Seas
03/06 RCI Explorer of the Seas
10/03 CCL Carnival Legend
07/94 CCL Ecstasy
bfein-We took a bus arranged thru NCL(available thru the NCL website) from Union Station in New Haven directly to the pier for a fee of $55pp roundtrip-it was very convenient.The bus was coming down from Boston and Providence. We took rail from Berlin,Ct.(free parking)&($12pp/rt) to New Haven-it was very stressfree and relaxing. We plan to do the same in Jan 08 when we will cruise out of NYC on the Gem.
bfein-You can go to the Amtrak website and book your rail tickets in advance-but you must pick the tickets up at a station-before you travel dates-Rail prices are quite reasonable when purchased in advance.