My favorites in order:

1.
-Valentine weather
-heartcastle block and wall
-surg block and wall
-pastel pink and purple blocks
-air vent
-heartstone block

2.
-Treasure blast weather
-heartcastle blocks
-glass blocks
-pastel blue/green/aqua blocks and wallpapers
-display blocks
-surg block/wall
-air vents

3.
-Night weather
-Art deco block
-black/red/yellow wallpapers
-Hidden door
-neutral solid blocks (brown, black, gray, etc)