I use NTUC frequently. Now with OCBC/NTUC card, they will waive off the delivery charge. I buy bulky items like milk powder, pampers, etc. Even vegetables and eggs. Good experience with them so far.
I tried Giant once, NTUC a few times, cold storage twice. Giant n NTUC quite gd. Cold storage is really bad, 1st time they missed out 4 tins of milk, 2nd time they were late.