The best replacement for tremolo is vibrato.

The best alternatives to tremolo are rated as following:
★★★★★  vibrato
★★★  hardtail
★★  fixed bridge
★★  no tremolo
★★  whammy bar
★★  floyd rose
★  univibe
★  trill
★  chorus
★  phaser
★  vibrato guitar
★  delay
  hardtail bridge
  vibe
  diatonic
  stoptail
  6 point tremolo
  non tremolo
  whammy
  supa trem
  not to tremolo
  flanger
  reverb
  modern tremolo
  tremolando
  edge pro
  callaham

Your alternative for tremolo is not listed? Suggest!
Speaking about tremolo, one probably shouldn't forget about locking nut.

Other search terms related to tremolo and their ratings are:
★★★★★ locking nut
★★ fixed bridge
tremolo
You have in mind a companion for tremolo and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of tremolo in all years. Click on graph for more.
tremolo
vibrato
hardtail