The big thing to know about Senjougahara, is that she is the man in her relationship with Araragi.

Well, it probably really depends on the execution. Giving someone characteristics that are common for the other gender is a little more interesting than simply giving them those that are often seen in their own gender - but it still does not neccessarily make a good character.
I should probably pick the Monogatari series up at one point.

Well, Momo is an interesting character, that's for sure. She is probably too interesting for the series she is in. Since everyone else is such a one-minded simpleton (exept for maybe Mikan) she can not truely show all she has got.
And not only for that reason is she pretty lonely. She always hides so many things about herself and tries to manipulate everyone.
Maybe I should also pick up this series again to see where she is going.

If only there were more hours in the day...

And no, I have not dug through your history. But I love Gurren Lagann and I have my own opinions on it.
I think for example that Rossiu is a good character. Sure, I would not really want to be friends with him. But everything about his fall in the latter half of GL is believable.
He bites off more than he can chew and he falls back on what he knew as a child - keep as many people alive as possible and sacrifice the rest for the greater good.
Not a nice thing to do but reasonable in his position. Not everyone can hit their head against reality until reality gives in...
And there are many, many, MANY people that become just like their parents even though they don't want it. That is a very human thing to happen.