As you are all about planning, I'm all about improvising. I would like a game to reward me for being able to change plans fast and to adapt to new situations. I come in with a plan, but half the fun is trying to take the one part that worked and figuring out what the heck to do now. I don't like games with situations where you had to have had a plan from the start of the game. It seems to limiting to me, but again this is just my perspective.
As with most things in videogames, it is best if you can succeed using a variety of approaches.
If you are the sort that likes to plan, the game should allow you to seek out information and advantages that will allow that approach. Equally, it should be possible to work out situtions for which you have not prepared from careful observation.
Too many games seem to delight in denying the player the opportunity to choose an approach. This simply results in players using internet walkthroughs to play, which is probably the surest indicator that the game was poorly designed.
This is my attitude as well.
And @neongreg, I also like and value surprises and improvisation. But I still see that as being separate and different from things being determined by rolls of dice.
