Depends - far out you can sometimes get decent fares, but usually the best prices are SQ / MI KUL-SIN-KUL. I have booked this and thrown away the return a few times.
Note at the moment a number of MI frequencies are cancelled due to the MAX issues, replaced by SQ in a limited fashion, so this may have tightened availability somewhat
Also worth mentioning that award seat availability is usually good and it is usually included in the "Spontaneous Escapes" promo which makes it even better value