It depends on your preferences.
38 Special vs. 9mm - Caliber Comparison - The Broad Side
A History of the Iconic .38 Special - The Shooter's Log
38 Super vs. 9mm Luger
Best 38 Special Ammo: Range Training & Home Defense - Wideners Shooting, Hunting & Gun Blog
9mm vs .45 ACP Berry's Bullets
380 vs. 9mm: Which is Better? - Pew Pew Tactical
Which would be better for personal protection, a 38 special +p or a 9mm? By better I mean effectiveness, ease of use and speed of firing. - Quora
38 Special vs 9mm In Snub Nosed Revolvers
9mm, .45 Auto, or .40 S&W: Which Handgun Has the Most Stopping Power?
380 vs. 9mm: Which is Better? - Pew Pew Tactical
38 Special Vs. 9mm Caliber Bullets
357 Magnum vs 9mm For Concealed Carry
38 Special vs 9mm for Self-Defense