Looking for mercenary sci fi

Hello, I've been really into military science fiction for a while now, but now I am looking for books where characters have a bit more freedom.

I do have a specific type of books I like to read and don't really stray from it, I am a very picky reader.

So if you know a book with a male main character (nothing against girls, I just like to imagine myself in his shoes), not an asshole and a badass in a sci fi setting, I would appreciate the recommendations very much.

If there is something like the Mass Effect setting with different types of aliens working together against a bigger threat that would be awesome too.

Thanks in advance!