From a shear defensive standpoint the G19 would be my pick. From a collector standpoint, I'd take the Colt Detective Special if it's in good original condition.
This is exactly what I was going to say. Glocks are great guns, they are still in production and when the latest silliness subsides they will still be around. Detective Specials are not being made anymore and are climbing in price at a steady rate.
Five months ago I went into my LGS to buy a G19 and walked out with a 1976 DS in mint condition that had just come in on consignment for slightly less money. The little Colt is like a work of art, the Glock is a utensil.