Joanne, I am assuming you mean with kids?
If so, a couple of ideas. Sorry only a few, our kids are just only getting old enough that we can take them out (other than to friends houses) with the effort v enjoyment ratio in our favour.
So are still finding our feet and look forward to reading more suggestions.
BBQ on the beach at Sentosa - we take one of those disposal BBQ's that look like a alfoil roasting tray
BBQ at one of the parks with BBQ pits
http://www.nparks.gov.sg/activities/act-bbq.shtml
Or cafe at one of above parks
http://www.nparks.gov.sg/activities/act-din.shtml.
Outdoor concert at the Botanical Gardens
http://www.nparks.gov.sg/calendar/cal-cal_of_eve.shtml
Hawker Centre - my kids love "Satay St" just off Robinson Rd in the city where we will sometimes meet daddy after work on a Friday.
Pasta Fresca on the East coast at the Seasports Centre
Hua Zhu Chinese Restaurant which is on Farrer Road under the HDB block off Empress Road - lots of room for the kids to run once they have had enough of sitting down (although if they are very little be prepared to run after them)
And last and more increasingly least...the "club"