The best replacement for fireball is frostfire bolt.

The best alternatives to fireball are rated as following:
★★★★★  frostfire bolt
★★  firestorm
★★  scorch
★★  meteor
★★  frostfire
★★  17 remington
★★  jack daniels
★★  goldschlager
★★  204 ruger
★★  powerball
★  cinerator
★  .17 hmr
★  fire orb
★  firebolt skyrim
★  22 hornet
★  fire eater
★  bob sinclair
★  bob sinclar
★  firestorm demon's souls
★  222
★  300 whisper
★  17 hornet
  freezing pulse
  ruger .204
  hot damn
  .204
  pyroblast
  polymorph
  20 vartarg
  sinfire
  300 blackout
  221 fireball
  peavey 6505
  incinerate skyrim
  god's wrath
  22 k hornet
  222 rem
  blackmore

Your alternative for fireball is not listed? Suggest!
Speaking about fireball, one probably shouldn't forget about angry orchard.

Other search terms related to fireball and their ratings are:
★★★★★ angry orchard
★★★★ rumchata
★★ horchata
★★ cider
★ redd's apple ale
apple cider
You have in mind a companion for fireball and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of fireball in all years. Click on graph for more.
fireball
frostfire bolt
firestorm