So many lesser known modern books to recommend.

Memoires of an imaginary friend

Dogs of war (Adrian Tchaikovsky one)

The devil's detective

Red rising

The painted man

As a more casual sci-fi reader I highly recommend Red Rising as a series. This first book is a very straightforward mashup of hunger games and Galica which is quite fun and enjoyable, but the series as a whole immediately creates it's own identify after that and I adore it deeply.