I don't own many MAC shadows. I've mentioned satin taupe before but I think its time to share some love for a shadow I don't hear much about - era.
Era is described as a soft golden beige. I'd say it has a little champagne in it. I think its quite unique in tone for a neutral shade. When MAC do shadows well, they do them amazingly well and era is one of those shades. Its buttery soft, smooth, highly pigmented, blends well..pretty much perfection in a pan.
Era works well swiped all over the lid or worked into the crease - its such a versatile shade. I like to pair it with shroom or with a little fig 1 in the crease. Its also one of those rare shades that would suit most skintones and eye colours. If you're looking to add a shade to your compact, this is definitely one to consider!