What kind of acting class are you looking for -- live theatre, film, commercial, voice-over?
Do you plan to stay where you are or can you move (even temporarily) to a larger city?
Backstage.com has a pretty comprehensive list of schools in NYC:
New York Acting Schools & Coaches
HB Studios has a pretty good reputation, AFAIK, and they offer a
six-week summer intensive program.
A couple of the "TV acting" schools aren't worth the subway fare -- DM me if you want the names.
Backstage.com also has its own set of forums dedicated to actors -- you might want to post your question there, especially if you're focusing on NYC. Actorsaccess.com has a similar forum that seems more oriented to the West Coast/LA.
Good luck!