Good place to start:
http://www.mikomos.com/wiki/Location:Israel (Thanks jack12 for the link)
Lounges:Botanic Gardens Jerusalem
Dan Accadia Herzliya
Dan Jerusalem Hotel
David Citadel
Inbal Jerusalem
King David Jerusalem
King Solomon
Mirror Bar- Located on the 2nd floor of mamila hotel. Good for daytime, nice and private. At night can get very loud and goyish.
There's a beautiful rooftop restaurant on the roof of the mamila hotel that is only rabanut (I think) but you can go and just get drinks. the view is STUNNING.
Restaurants:Cafe joe (cup of joe)- Corner of king gorge and keren kayemet: nice quit coffee shop with good coffee and staff that doesn't bother you. It also has a mehadrin hashgacha (dont remember which) so you can also eat there if you want. Additionally they seem to have a bar with access from the restaurant if that's your thing.
Cafe Cafe- on emek refaeim street: good food, good coffee, nice and quit.
Polly- yehuda street 1 (baka): Classy Italian, very good food, great ambiance. (Try the lower, more intimate level where they have a real fireplace!)
Fun stuff:Gani yehoshua- Big park in ramat gan that has grassy areas, swings, a pond with paddle and mother boats for rent, picnic areas, etc'. There's also a (lame) skating rink across the highway. (5-10 min walk)
feel free to add to the wiki.