Route 36 from orchard to marina bay is basically a city tour for bus fare. Runs along orchard road, past colonial district, around marina bay, then to gardens by the bay. Upper deck front seats give you views without the hop-on-hop-off markup

Takes about 45 minutes end to end, buses every 8-10 minutes. Use your ez-link card and its cheaper than coffee. Tourist buses charge s$40 for the same route while you get the real singapore experience with locals commuting to work