Drinks and Dinner in North Slope?
There is a great little place called Sorrel just north of the "north slope", but worth the trip (just across flatbush from 7th avenue). Very nice place with open dining room on a tree lined street, a prix fixe menu of "farm fresh" french-ish/new american food...our meal there was excellent. The last time I was there the waiter put a lot of thought into matching the wines with the meal and he was spot on. It's nice but casual and you should be able to get a table. Otherwise I'd say Rose Water, maybe Tempo. You'll wait forever at Al Di La.
Stone Park & RoseWater are your best bets for New American. I'd say RW is cozier and romantic, but SP's food is probably more consistent.
Blue Ribbon is a little more traditional, comfort-foody than SP & RW.
Al Di La will be difficult to get into on a weekend, but the wine bar might be a nice place to get a drink while you wait, if it's dinner & drinks you're looking for. If you look at Italian places, might as well throw Tempo into the mix.
As for bistros, French options include Cocotte, Belleville and Moutarde, none of which is outstanding.
I don't recommend Black Pearl. I had an overpriced meal there and have heard nothing but bad things from friends.
I think the best New American places are in Carroll Gardens/Cobble Hill: Chestnut, Grocery, Saul (all of which have been reviewed on this board).
There's been some negative comments about Black Pearl (Union Street close to 7th Avenue) but I was there this week and had a very good meal. It's not cheap by Brooklyn standards, but the cocktails are good, the place is attractive, and if you like seafood, they have a seabass that shouldn't be missed.
Blue Ribbon...an eclectic selection and good wine list.
Your post is too broad. There are a bunch of great places to eat in the area. Stone Park also comes to mind. I also reccommend Al Di La or Convivium, though neither are considered American, I consider them both very good and worth trying.
You may want to do a little wandering in the area and see what intrigues you. Reservations on a Friday are a good idea if a place accepts them, but often if you want to wait and have a drink you should get a table in due time.
Can you give some more info to narrow down suggestions? What kind of food are you looking for? What's your budget? Also, what are you thinking of when you say "North Slope" - that can mean differnt things to different people - btwn 5th and Prospect Park West north of 9th Street?