Hermione was very brave and loyal person although she was brainy. She also may have ended up in Gryffindor because she wanted to go into Gryffindor. "Books and cleverness! There are more important things, like friendship and bravery!" So it's obvious that Hermione values bravery over cleverness, and so was placed in Gryffindor, where she'd have the best chance to develop her courageous side.
There not really an answer to this question because Hermione could have been placed in any house because she was Brave and had nerves like a Gryffindor, Intellgient as a Ravenclaw, Loyal as a Hufflepuff and as Cunning and Noble as a Slytherin.
Hermione understood courage. And that being brave wasn't the absence of fear, but being able to keep going on and remain loyal, despite your fear.
Despite Horcruxes, Harry's on bad attitude at times, Ron's immaturity at times, danger to her family, Molly's and other's betrayel when they believed everything in the newspaper about her, she remained true to what she believed.
I don't question her bravery - Hermione has more guts than the other boys sometimes.
But I think she was placed in Gryffindor because she needed to be there actually. I believe she should have been sent to Ravenclaw as her brain power is her main characteristic.
I think the Sorting Hat is a bit of a prescient magical artefact and he may have seen the future. That Harry may need help from brains, like he needed physical help at times (Ron). Honestly - and the boys admit it themselves - how could they do without her ?
