Here are a few that I own and really like.
MTAC ~$80. In this pic it's set up for my Sig but I also have shells for my Commander and G19 / 23. IMO this is one of the best holsters for the money.
Milt Sparks VM2. ~$110 This is my favorite G19 / G23. It is very comfortable and conceals very well.
Galco Triton. ~$40 All Kydex and surprisingly comfortable. This one is my go to for quick trips as it slips on very quickly and conceals very well. I didn't expect it but this one is pretty comfortable to wear for extended periods of time.
Blackhawk makes a great IWB for the money. ~$40 This one works very well, is comfortable and conceals well. I have one for my G19 /23 and Commander.