We chose Renaissance Cruises, 
because they visited the ports we really wanted to see, and the price was 
very 
reasonable.  We would have liked to have spent more time in Greece, but that
wasn't option since the cruise also included charter flights to and from
New York.  We also liked that all of the Renaissance ships are completely 
non-smoking, and no children are allowed.  We also considered 
Windstar 
Cruises, Orient
Lines, and Radisson Seven Seas 
Cruises.
 
We wanted to see more of Greece than just Athens, so we
rented a car from Budget and drove
ourselves around the Peloponnese.  Driving in Athens was a little scary, but
once we got out of the city there were plenty of signs in both the Greek
and Roman alphabets and it was easy to get around.
 
The cruise included three nights hotel before and after the cruise.  We 
stayed 
at the Athens 
Hilton for one night after we returned from our trip to the Peloponnese.
It had a nice big bathtub, but was otherwise pretty generic.  The bar on the 
top floor has a great view of the Acropolis and a very 60s decor.  We also 
stayed at the 
Hilton
in Istanbul.  It's located in the business district, about 10-15 minutes
by cab from the Sultanahmet district where we spent most of our time.  We 
would have preferred to stay closer to stuff we wanted to see, instead of 
having to take cabs every day.
 
Overall the cruise was nice, but we think we're just not cruise types.
Although there were plenty of choices in the dining room every night, they 
were always American style -- never the local cuisine we would have liked to
try.  We thought their suggested tips were
much too high ($17 per person per day), so we tipped as we would have for 
similar service in a land-based resort (about half as much).  We really 
enjoyed our private balcony -- it was nice to be able to lounge around and
watch the coast go by or read a book.
 
Before leaving for the trip, Kimberly read several books to get a better
sense of the history of the area.  Paul is still planning to read these
"soon."
Details
We decided that a cruise ship was the best way to get around, since the 
ferry system seemed to require lots of time and patience.  Especially early
in the season, schedules tend to be unreliable, and transit times are long.
Another option was to fly between the islands, but we thought it would be nice
to spend time on the water.  
We brought the Frommer's Greece guidebook 
with us, and it had very good descriptions of most of the ancient sites we 
visited.  We also brought the 
Rough Guide: Turkey.  
For some reason, we thought the information was confusingly arranged; several 
times we couldn't find information on some site that we knew we'd read about 
before.  The 
Istanbul city map 
from Lonely Planet was great.  It had everything we wanted to see clearly 
marked, and had several maps at different scales.