The best replacement for blocks is bricks.

The best alternatives to blocks are rated as following:
★★★★★  bricks
★★★★★  stepping stones
★★★★  legos
★★★★  lego
★★★★  sectors
★★★  delegates
★★★  zombies minecraft
★★★  selectors
★★  add a leaf
★★  stacks
★★  concrete blocks
★★  eclipse
★  small blocks
★  patterns
★  poured concrete
★  stepping stones poem
  duplo
  monomers
  leaf springs
  periods
  dev c++
  shackles
  clusters
  citiblocs
  bombs
  gu
  big blocks

Your alternative for blocks is not listed? Suggest!
Speaking about blocks, one probably shouldn't forget about arc.

Other search terms related to blocks and their ratings are:
★★★★★ arc
★★ wagon
You have in mind a companion for blocks and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of blocks in all years. Click on graph for more.
blocks
bricks
stepping stones