The List
There are 80 4 letter words with B as the last letter. The highest scoring is ZIMB at 17 points in Scrabble, though Words With Friends prefers JIBB at 19.
BARBBIBBBLABBLEBBLOBBLUBBOABBOMBBULBBURBCARBCHIBCHUBCLUBCOBBCOMBCRABCRIBCURBDARBDAUBDIEBDOABDOOBDORBDRABDRIBDRUBDUMBFEEBFLABFLOBFLUBFORBFRABFRIBGAMBGARBGLIBGLOBGRABGRUBHERBIAMBJAMBJIBBKEMBKERBKNUBKRABLAMBLIMBNIMBNOOBNUMBPLEBPROBSCABSIBBSLABSLEBSLOBSLUBSNABSNEBSNIBSNOBSNUBSORBSTABSTOBSTUBSWABSWOBTOMBVERBWARBWEMBWOMBZIMB