I was born and raised here in North Texas, and have live here all but four years that I was in the Marine Corps.
Of the areas that you listed, Celina would be my choice simply because it's a small town, nice area, great school, great football team, and close enough to DFW to hit the big city when you need to. Frisco, McKinney, and Plano real estate is at a premium; nice areas but expensive and steadily growing into big cities. I don't know much about Farmersville, seems like a nice area, but that's about where my knowledge ends.
Thank you sir. Really appreciate it. Liking Celina a lot. Great to get first hand knowledge. Thank you Raburn2906.