Merchants that accept AMEX (Amercian Express) credit cards:

FOOD & BEVERAGES:

Fairprice
Giant
Cold Storage
Jason's
Market Place
7-Eleven
The Coffee Bean & Tea Leaf
Starbucks
Astons
Imperial Treasure Super Peking Duck
Swensen's
Sushi Tei
Ichiban
Tunglok
The Cocoa Trees

FASHION/SHOPPING/ESSENTIALS:

Guardian
Watsons
Uniqlo
BHG
Isetan
Tangs
Popular Bookstore

TECH & ELECTRONICS:

Challenger
EpiCentre

SERVICES:

M1
Starhub
SPC
HDB seasons parking online payment
Agoda
NUH

LEISURE:

Cathay Cineplex
Shaw theatres

NON-AMEX Merchants:

Singtel (used to no longer now)
Golden Village ONLINE
Road Tax
Parking Fines
Ma Kuang TCM
Pastamania