While I prefer larger and more powerful cartridges like .357 Magnum and .44 Magnum myself, I think that a medium-frame .38 Special revolver is a highly underrated self-defense weapon and would not feel at all uncomfortable if it was all I had to defend myself with.
In a medium-frame, all steel revolver, the recoil of a .38 Special, even with +P ammunition, is mild enough that I've yet to meet anyone who couldn't handle it after a moderate amount of training and familiarization. In its better loadings such as Remington 158gr LSWCHP +P or Speer 135gr +P Gold Dot, the .38 Special gives comparable performance to some of the better 9mm loadings and is more than enough gun for most situations if the shooter can do his/her part. The simplicity of a DA revolver is, in my mind, very advantageous to inexperienced or "casual" shooters not only because of the absence of a manual safety, but also because of the longer, heavier yet smooth trigger which takes a deliberate effort to pull and the ease of verifying whether the gun is loaded or not. Finally, while not available at the bargain basement prices they used to be, a good medium frame .38 Special such as a S&W K-Frame, Ruger Security Six, or Colt Official Police is not particularly difficult to find in the $300-400 range and sometimes less if one happens upon a good deal.
Smith, and Wesson, and Me. -H. Callahan
Well waddaya know, one buwwet weft! -E. Fudd
All bad precedents begin as justifiable measures. -J. Caesar