The best replacement for cassette is freewheel.

The best alternatives to cassette are rated as following:
★★★★★  freewheel
★★  fm transmitter
★★  freecoaster
★  8 track
★  freewheel bmx
★  cd sound quality
★  reel to reel
★  cd quality
★  freehub
  11 34
  micro cassette
  dura ace cassette
  freecoaster hub
  squishit
  12 25 cassette
  ultegra
  minidisc
  regular cassette
  hesh 2
  freewheel hub
  sram pg1070 cassette
  105 cassette
  shimano cassette

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

Other search terms related to cassette and their ratings are:
★★★★★ aux
★★★★ audio jack
★★ compact crank
★★ cd recorder
★ sram derailleur
★ shimano
★ sram chain
shimano derailleur
camcorder
shimano shifters
You have in mind a companion for cassette and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of cassette in all years. Click on graph for more.
cassette
freewheel
fm transmitter