I live in Colorado and swear by conditioner due to our low humidity. I use conditioner on our leather furniture as well. I agree with everyone that soap and water work best for cleaning.
Clean up spills quickly (like coffee, kids fruit punch juice boxes etc).
I personally like Lexol cleaner and conditioner. You can get them in bottles and you supply the rag/chamois or you can get presoaked wipes. Lexol | Lexol