There's not a huge number of games where we could claim that the CPC version was superior to the C64 version.
Actually I could argue many games that came out both were possibly overall better on CPC.
Bombjack I couldn't really say as I never played it much. Wasn't a fan of the arcade game.
Favorite CPC games: SwitchBlade, Stryker in the Crypts of Trogan, Turrican II, UN Squadron, Oh Mummy