Sci fi books that read like character focused fantasy for a beginner looking to get into the genre?

I am interested in reading Sci fi, specially space opera, but from what I have gathered from friends that do read scifi is that it's (Very generally) a genre focused on cool, deep, interesting or innovative ideas and themes, and characters take a secondary role. Of course, I haven't read any Sci fi books and I don't know all of them, so I want recommendations.

I am interested in a good story with great characters, it can involve war, politics, exploration etc, maybe akin to halo or mass effect. I would prefer if the books were either modern or not too difficult to get into. I know nothing of Scifi so please recommend me anything, even if it seems the most obvious answer.

I would also prefer if they were more mature books and not YA, which isn't my cup of tea. The only books I know of are Dune and Gideon the Ninth (Which I haven't read but got them on my list).