Best is pronounced BEST (IPA /bɛst/). Voice the 'b' — start with vocal-cord vibration before opening lips.
IPA: /bɛst/
Syllables: BEST
In 69 attempts by 21 learners scored in the SayWhat app, the sound most often scored red in this word was /t/ (13% of attempts).
Common ESL mistake: Learners (Arabic speakers) say 'pest' using voiceless /p/.
Tip: Voice the 'b' — start with vocal-cord vibration before opening lips.