KCLE (Cleveland Hopkins International Airport, Cleveland, OH):
The Spectator Deck is at the end of Concourse B which is past the security checkpoint, so you must have a ticket on Southwest Airlines, Delta Air Lines, United Airlines, or Air Canada (or their regional carriers) to have access to the deck. As far as I can tell, the open-air portion of the deck is closed indefinitely due to the terrorist attacks (the way it was set up, you could have dropped something down to the Southwest ramp with little difficulty.)
The Spectator Deck's enclosed section (the remaining area open to passengers) is enclosed in glass that casts numerous reflections and is pretty scratched up. You can't get the right angle for most shots, anyway. You would have to posess a zoom lens to focus on the actual aircraft rather than window reflections.
KCAK (Akron-Canton Regional Airport, Green, OH):
The Spectator Deck is still open but the open-air section has been closed since any of the current security can remember. You can get an OK view of landing aircraft but it is pretty much obstructed and the viewing angles create optical illusions. It's only an hour away from me and I've only gone once due to the difficulty of viewing there.
KCVG (Cincinnati-Northern Kentucky International Airport, Covington, KY):
I just (like in the last five minutes) got a return e-mail from someone at KCVG who said that their Aircraft Viewing Area has been reopened. While this is *not* in the airport, it is on the ring-road around the east side of the airport and is above the approach end to Runway 9. It is a beautiful viewing area and I might try to go down there again sometime this fall. Of course, it's Delta Delta Delta Delta Comair Delta....
KBKL (Burke Lakefront Airport, Cleveland, OH):
As far as I know the terminal is open, but you don't get any good views, just flashes of airborne small fry. It's almost exclusively small GA anyway.
KCGF (Cuyahoga County Airport, Richmond Heights, OH):
No good viewing locations. Exclusively GA.
Up, up and away!