8 people in their forties, love good food & great wine & fun, in Manhattan
Sadly, you've two too many people to go to Babbo... they plateau at 6-tops.
Of the four-starrers, I'd say Eleven Madison Park is the least staid, and Del Posto the second-least. They're the only two without jacket requirements. But people will be - while not raucous - certainly having a good time at the others. Le Bern is probably the most "reverential" in vibe of them, IMHO. JG the most "corporate", Daniel.... well, I just don't really like Daniel that much. But they'd be fine there, if they're cool with the jacket requirement. I actually greatly prefer DB's (supposed) "second tier" restaurant, Cafe Boulud. The food is much more exciting.
On the next level down, price-wise, there are some good options:
For food that's a little more adventurous, WD-50 or Public.
For cuisine a little outside the norm, Aquavit - the new dining room, while formal, isn't as staid as the old one.
For upscale (but hearty) spins on comfort food in a more "neighborhoody" vibe, Marc Forgione.
For simple preparations of top-notch ingredients, Craft.
For a boisterous scene, Acme, Monkey Bar, or The Dutch.
For a more "sceney" scene (especially on the weekends), Beauty & Essex.
If you'd like a beef-centric meal, Manzo.
If you'd like to go (non-sushi) Japanese, Morimoto - solid wine selection for an Asian place, and a good sake selection if you'd like to explore that.
If you'd like to go Chinese, a banquet (or just a bunch of shared dishes) at Ping's (more creative) or Oriental Garden (more traditional) (BYOB at either - bust out those winter whites!)
50 Clinton Street, New York, NY 10002
65 E 55th St, New York, NY 10022
20 East 76th St., New York, NY 10021
Eleven Madison Park
11 Madison Ave., New York, NY 10010
1 Central Park W, New York, NY 10023
85 10th Avenue, New York, NY 10011
155 W. 51st St., New York, NY 10019
43 E. 19th St., New York, NY 10003
14 Elizabeth St, New York, NY 10013
22 Mott St, New York, NY 10013
88 10th Avenue, New York, NY 10011
210 Elizabeth Street, New York, NY 10012
9 Great Jones St, New York, NY 10012
60 E 54th St, New York, NY 10022
134 Reade Street, New York, NY 10013
131 Sullivan St, New York, NY 10012
200 5th Ave, New York, NY 10010
Beauty & Essex
146 Essex St, New York, NY 10002