Ray

You can't go wrong with the flies that Rel recommended.

The Hudson also gets a large number of herring running up it's tribs, so a blue over white deceiver is a good bet, some at least 3/0.

If you want to go an extra mile, these are more specific herring imitations that work very well, and seem better at finding large fish:

Patrick Keliher?s herring pattern
http://www.reel-time.com/forum/showthread.php?t=48978

or a flatwing like this beauty by Mark Gustavson:
http://www.panix.com/%7Epg/flyfishing/alewife.html

I've also had some luck with all chartreuse stuff like deceivers in off-colored water-- perhaps the visibility stands out, which may also be why black is often so effective as Rel points out. Some size 2 Ray's Flies for smaller minnows (silversides etc) that seem to be all over the trib mouths and marshy areas near shore, 1 or 1/0 Chartreuse clousers and large 3/0 or bigger heavily weighted 1/2 and 1/2's for fishing drop offs and deeper holes in swift water might be good too, and are pretty generic flies for stripers and everything else if you are looking for some more simple patterns...

Hope this helps.

peregrines