All the boxes are pretty different so it’s good to get them all.

The small box and gift box are similar:

small box neko atsume english guide
small box
giftbox neko atsume

The cats stick their heads into the cake box (their tails swish back and forth (animated) or just stay still with their tails sticking striahgt up, so cute!):

cake box neko atsume english guide
cake box

Pretend to be a tortoise with the medium sized box:

medium box neko atsume english guide
medium box

Squeeze into the box car:

box car neko atsume
box car

Pretend to visit someone in the house deluxe:

house deluxe ex neko atsume english
house deluxe ex

Pay Cafe San a visit in the Cafe Deluxe:

cafe deluxe neko atsume english
cafe deluxe

Ride a train:

train item neko atsume
train deluxe

Special items: house deluxe ex (Koi Koi San), cafe deluxe (Cafe San / Sassy Fran) , train deluxe (Ekichou San)

You should get all the box items, and either the gift box or small box.