In the vast majority of the harem anime and mangas like Sakura Taisen, Infinite Stratos etc. you can see which one of the girl is the obvious choice and in 99% of cases that's the one the guy chooses, it's boring.

For example in Infinite Stratos, the guy is surrounded by five girls from the academy, Shinonono Houki (Japanese), Cecilia Alcott (English), Huang Lingyin (Chinese), Charlotte Dunois (French) and Laura Bodewig (German), even if only a couple chapters are out, you could already see from the very beginning which girl was the obvious choice, which is Shinonono Houki (Japanese guy + japanese girl), how proper and politically correct, but it's kinda boring because it makes all the other stuff that happens between the guy and all the other girls seem like aimless and a waste of time, since you already know which girl who is really gonna end up with.

So I am looking for harem mangas which are the opposite of that.

Most likely you've already read this, but just on case, there's Ichigo 100%

Maybe The world God only knows? Haven't read it but it seems appropriate.

Hayate no Gotoku! it could be...

________________
What I like in Trivial Pursuit style. Pick your category: