What are you going to do with your G19? For range/IDPA/so on use, a kydex holster is great. Nothing wrong with a Fobus. At a combative pistol course I took, a Blackwater instructor was there, and he used a Fobus for his G19. He got some crap about it, and he said he loves 'em. He had about four of them in his truck.
If you want some thing just simply to hold your pistol while you walk out to a range, and you don't care about being able to draw fast or anything, a cheap crappy nylon holster would be fine. Just don't carry with it cocked and locked. Those holsters are dangerous with Glocks in my non-professional opinion.
I don't know about a holster that doesn't require a belt for a G19. There might be an ankle holster out there, but that's a lot to hump on your ankle. There might be a coat pocket holster, but that only works if you have a coat on(obviously). Even the paddle holsters cause problems without a belt. I've seen some funny from a guy that was drawing from a paddle holster with no belt.
Your needs should dictate your equipment to a large degree.