I looked at this recently, and it looks like bcrypt is outdated. FPGAs and ASICs have gotten much better since bcrypt was popular, so Scrypt's higher memory usage is a huge advantage. It seems like scrypt vs argon2 is the question now. I went with argon2 for its hybrid id version, but if you want something more tried and true, scrypt is likely better. It's only in the last year or so people seem to agree that argon2 is ready for real use.