1. Stay at Marina Bay Sands and check out Infinity Pool.
2. Have a drink at Clarke Quay at The Clinic.
3. Take a ride on the Singapore Flyer (at night).
4. Drinks at Altitude Club or Swissotel Helipad.
5. Walk down Orchard Road but leave your wallet at home so you don't spend your life savings.
6. Eat at food stalls and be adventurous. Avoid Kopitiam, that doesn't count as a food stall. Get some chicken or duck rice. Yum!
7. Wicked is playing at Marina Bay Sands -- see it if you haven't already.
8. Stay away from Geylang and the KTVs.
9. Don't waste money on cab fares. MRT is more convenient and fast/cheap.
10. Use SQ First Lounge at Changi. It is exceptional.
11. Go to Little India and China Town.
12. Don't bother with Duck Tours. It's not worth time/money.
13. Don't bother with Hop On/Hop Off Bus Tours, also not worth it.
14. Bring an umbrella and a lightweight waterproof jacket for sudden downpours.
15. Go to Raffles Hotel/Bar, but order a normal drink. Singapore Sling is OK, but too small and costs a bloody fortune.
16. Night Safari is very good unless it rains.

Really, lots of good food/drink opportunities in SG, but probably not where I'd go for an employer sponsored holiday. Too bad this wasn't a month ago, Singapore F1 Night Race is SPECTACULAR!

Singapore is a great hopping off place to other nearby SE Asia countries. If I were you, I'd transit at SIN and hop a flight to BKK for a day and a half. So much to see in BKK and an AirAsia flight is CHEAP+CLEAN. Alternatively, Bali is practically across the street and also a super cheap fare.

Good luck. PM me if more questions. I just moved back to USA from living in SG for two years.