A friend of mine has a 97 SH model.  He's had an O2 sensor replaced.
His ATTS oil sensor is bad.  The connector to his driver-side (left)
headlight is now faulty as it comes on and off.  Some Honda's suffer
from leaky distributors (which are quite expensive, I assure you).

If accidents bother you, look out for that.  The hood, truck, and
fenders should still have their sticker that has the VIN.  Check all
the glasses to ensure that they are the Honda brand.

Honda's are also very specific on their power steering and coolant
fluids.  Make sure that they are Honda brands and not aftermarket.  

Make sure that you have all the factory keys.  A replacement with
built-in anti-theft chip will cost you big bucks.  While you're at it,
make sure that you get the anti-theft code for the radio.

My brother's had the 2000 base model and achieved 26mpg 50/50 split
between city and freeway.  He got 30mpg on a mostly freeway trip.

Looking at purchasing a 1998 Prelude with 85 thousand miles!
Any thing I should look for as the dealer advised the car is OK I would
still like opinions on what else. What kind of fuel mileage should I expect?
1/3 city 2/3 highway at speed limit.
Your advise will be appreciated.Any cool sites on Preludes would be
appreciated.