1)Chabad of the upper east side 1264 East 77th street (between first and york) - A pretty building with a very consistent minyan. This is also the location of the women's mikvah, and a dishes mikvah, so it's likely you know the spot if your married and living here. What it says about you: you're a chabadnik, related to a chadbadnik, a ba'al teshuvah, new to the area or shy and don't know anyone around here.
2)Congregation Bnai Israel aka Ralbag, 335 East 77th (between first and second) - It's the lower level of the building, the rabbi lives upstairs. This shul usually has an early megillah reading etc. for working people. Almost always a kiddush every shabbos. The ladies section is a little small but adequate for the amount of attendees. What it says about you: You're young, or wish you were, and you are a little yeshivish. You are a kiddush club, mainstream, chevra type of family. You look to your shul for socializing and setting up play dates for your kids.
3)Edmond Safra Synagogue, 11 east 63rd street (between fifth and madison)- The prayers here are in the Sephardic style. The building is beautiful but the architecture sacrificed looks for design. This is not a large problem on your average shabbos but on holidays/megillah readings you should come early for a seat. Ladies section is above the mens section. Massive and upscale kiddush every shabbos. What it says about you: You're Syrian, Mexican, or some other variety of the sephardic persuasion. You may be on some sort of rotation between this shul and our parents shul in brooklyn. There is also usually a large amount of travelers. Or you could just be in it for the food, which is really good.
4)Park East Synagogue, 163 East 67th street (between third and lexington)- A mainstay of the community for years. Famous for its chazzan and visits from the pope. Usually does not have problems with funding or a minyan. Very popular for maariv. What it says about you: You are a traditional type of person. You send your kids to ramaz and possibly consider yourself "modern orthodox" or "traditional". Or you may also donate, contribute to the shul but only really attend for holidays.
5)Yorkville Synagogue, 325 East 78th street (between first and second). - the crowd is a little older, but they are starting to attract a small core of younger folks. The rabbi gives a great speech every other week at the kiddush, cholent and learning program. Ladies section is upstairs and very large and spacious. What it says about you: You are orthodox and may even label yourself as "frum". You may be a retired Dr. who read the rabbi's medical ethics books. You may also be young and like a good speech.