The Hunt
The big brokers: (Corcoran, Citi Habitats, etc):
Many if not most of the listings on these sites are fake or expired. They seem to put up nice reasonable looking apartments (but actually unavailable) to draw you in. Many of the brokers we've dealt with have been lazy, rude, or incompetent... All this joy for 12-15%... I know, I know, welcome to New York. After 10 years away you forget what a nightmare house hunting can be. For reference, here in LA a few years ago myself and 4 friends rented a 1920's mansion from record producer Rick Rubin with a handshake and one month deposit. The rent was around $5000/month. In NY that same rent gets you.... but why go down that road. Must accept new reality. Ok. Next.
The MLS
This is a site for buyers but can be useful to get building info if there happens to be an apartment for sale in a building you are considering.
Rent Direct
This company has lots of listings for big horrible buildings. The site is hard to navigate and search. Also there are many bait and switch listings.
Craigslist
I've been disappointed by craigslist new york. In LA and San Francisco craigslist is probably the best way to find an apartment, but in NY it's full of bad broker listings and quacks. Disappointing.
Edit a few weeks later: If you are diligent you will eventually learn how to weed out the bad seeds. Craigslist is still the best site to find a no fee apartment in New York.
Loot
We didn't discover this site until too late, but it's a good source for by owner listings. Especially down in the East Villiage.
MLX.com
This is by far the best site I've found, but it's not free... 4 nice features: full addresses are shown, the listings are good, detailed building info, and email updates. It's not perfect though--the user interface is busy, you can't sort in detail view, and there are still too many expired listings. After one day on the service Jenn finally saw some places she liked. The one she REALLY liked was out of our price range (6500/month and it already had 2 offers) but then again it was a 4 story brownstone:
Edit a few weeks later: In the end MLX wasn't that useful for us. Most of the apartment listings were for big high rise buildings.
--
Jenn says Olivia has been kicking much higher than last week. I wonder if that means anything. Maybe she gets tired of all the traipsing around in the heat...
--
ps I should note that on the buying/selling side we have had some great experiences with NY brokers. Louise Devin of Brown Harris worked tirelessly to sell a family apartment on 63rd Street and in Brooklyn Heather McMaster of Corcoran has done a fantastic job of letting us know the lay of the land...