gudel, I don't know what your level of experience is so I might be preaching to the choir. Avoid floppy fabric holsters like they are the bubonic plauge.
Fabric holsters have one advantage, they are cheap. Other than that they are very bad things. They tend to "flop". They are not solid, they are often not in the same place when you try to reholster them. They offer very little in the way of retention, other than goofy and slow to utilize, slow to reactivate plastic thumb straps. And these are the good ones with reinforced tops, the really crappy ones aren't reinforced and require a two hands to reholster because they collapse once the gun is removed. Plus in my experience the nylon is harder on blued guns than anything else.
Leather or Kydex is the way to go. Leather for style, Kydex for functionality. A good kydex holster will enable you to stand on your head and the gun won't fall out. Yet, when you try to draw it the gun will pop right out.
I've got leather holsters from some of the top holster makers in the business (Milt Sparks and Mitch Rosen) however my serious business holster is a Kydex G-Code (Scott Evans).
I like Kydex because it offers superb retention, it is light, it is thin. My favorite G-Code is the paddle. Rock solid when it is on, yet easy to take off when you need too. Quick to put on if you are just going to run to the store also.
I like the G-Code the best of the Kydex holsters because, 1. The fit is superb, they fit the gun like a glove. 2. They have a sweat guard, to keep you from reholstering your shirt with your gun. 3. Scott is a great guy, and I believe in supporting businesses populated by good folks.