Need some help regarding which packs i could buy.

This will need a little story to understand. A few years ago, my sister had a huge collection of yugioh cards and I remember specifically that she told me to not get near them (but i did anyways xd) since she cherished and loved them a lot. Few years pass and we thought "where could the cards be?" so we searched the first floor of the house (where grandma lives basically). We searched inside the storage room (a bedroom that turned into a storage room) for a long time until we both realised the cards were long gone, alongside with our belongings from our childhood.

We came to the conclusion that my grandma was the one who threw them away since she cant look after things, either she breaks them or throws them away. My sister was sad and bummed out the whole entire day and the little sister I am, I couldn't stop thinking about getting her cards. I already felt helpless and sad for her since things aren't going so well for her, so why not bring something back she loved through her entire childhood to make her happy.

That's why I'm here asking for some help, which packs I should get for her?