When I want to build beautiful buildings I go to creative mode -- that way you don't have to slave around trying to find materials to build it in the color you want. And those damn creepers don't blow up your hard work.
I play survival when I want to go full on caveman. Haha.
So there really is no better, but if you want a challenge then definitely play survival. If you want to build, go for creative.
I agree, it depends on what mood you're in. If I want to create some cool buildings and be "creative" well I obviously end up in creative mood. I usually go on the web and look up interesting buildings and designs that I try to copy.
When I'm playing with my friends, I usually play survival. It's much more fun when you have people with you and you're all trying to survive together. I think I generally prefer playing survival mode as it feels more like a game than just building interesting buildings or objects
I prefer survival mode. When using creative mode, you do not have to work for anything and can build anything without gathering the materials yourself. On survival, you actually have to gather everything yourself while worrying about perishing from evil mobs. In survival, you actually have to work for what you make.
I personally prefer creative mode. While survival is good and all the whole reason I bought Minecraft in the first place was to be creative and build. To me there is nothing better than building a hotel or a nation's flag. I've even recently built a bad replica of a viking long ship. I just like to mess around and see what comes up. I'f I think I can work with something then I go with the flow. If I don't like it I'll burn it to the ground. One of my biggest gripes with survival mode is going down into a cave and when you're trying to get out you accidentally dig into a lava pit and die, losing all your stuff. That and when you get lost in a cave for 2-3 hours and you can't just dig straight up because chances are you'll die and have to redo all that hard work.