I personally develop games that I enjoy playing. If there's something I ever go "i wish someone would make this" then I go "hmmmm" and then I start writing code and before I know it I have a project on my hands (which is how my current one started)

Everyone's different, I realize, but developing a game that I personally have no interest in is also not very fun for me (speaking from experience).

When code creates things that are beautiful and that I didn't fully predict, that is what I love the most. ... I think I began with the desire to create worlds that follow my rules. Being the god of a digital world is very appealing. Realizing ideas is also pretty appealing.

That sounds very Molyneux of you: set up rules and watch the results without much, if any, intervention. I agree with BKrenz in that it sounds like you like working with AI behaviors and watching how new rules interact with existing systems. If I were to guess on a game style that you would like designing based on the information I have, I would have to go with the Simulation category. SimCity, Black&White, Spore, and the like. Sandbox if you want, or set goals to achieve, but ultimately it's about creation and seeing the results of that creation.

That's the kind of game I think you'd like to make.

The problem that I'm facing (and have faced on all of my games) is that I'm never very motivated by the design. I'm designing games that I think will please the crowd and will fit in my ruthless schedule, not games that I will personally enjoy

I am going to turn this around on you and ask the following:

In designing games for other people do you gain enjoyment from knowing that you have a market who enjoys your game?

If you build a game that you would enjoy playing would you find that having done so that being so much in the digital god seat you will effectively has dissected everything you enjoyed into a product that does not bring joy simply because you are over-familiar with it?

On your first question, yes, I do love it when others like my games, but I don't really experience that because most of my games are not good enough yet (but I try as hard as I can).

Yes, I suppose it is true that I would be over-familiar with it.

Maybe I'll just keep doing what I'm doing and figure it out in time.

Stay true to yourself and be less worried about trying to market some uber popular game. If your goal is to come out the pipe and start creating five star games, you are going to be setting yourself up for an impossible task.

If you enjoy what you are doing, as you improve chances are you will implicitly start creating games that others are drawn to as well.