Mattress topper recommendation?

[sandandsea]

My son complains that his mattress is too hard. He prefers very soft mattresses and currently has the softest memory foam mattress we could find but I have to admit he’s right. It is hard, especially compared to our Sleep Number with a very low number setting. Any recommendations for a topper to make it soft? Are the down alternative actually soft and do they make a difference?

[simpsongal]

I always had an egg crate on top of my mattress. Might that work? My folks had the my pillow topper and didn’t like it (smelled like chemicals).

[expectantsteelerfan]

My kids both have The Big One mattress toppers from Kohls on their beds and like them.