If you're looking for light/pleasure reading agree with Nick about The Body Keeps the Score. More related to neuro, but Oliver Sacks also has some interesting reads, the most popular being "The Man Who Mistook His Wife for a Hat". For more of a fictional perspective, "The Curious Incident of the Dog in the Night-Time" is a very easy read and is written from the perspective of an autistic adolescent. Not really scientific, but very interesting in terms of understanding the thought process and has been given some credibility by both medical professionals and individuals in the ASD community. I'll also second the suggestion of reading some historical books from some of the more influential psychiatrists/psychologists (Freud, Jung, Kraepelin, etc).
More related directly to psychiatry, I'm currently reading "Uncommon Psychiatric Syndromes" which talks about some zebra diagnoses and cultural phenomena. Very interesting for those interested in the more bizarre side of our field. I'd also recommend reading or at least skimming the original DSM and DSM-II. They're both pretty short (~130 pages) and easy to read while giving a look into how diagnoses evolved and how much the field has changed in the last 60-70 years.
If you really want to look into more clinically relevant stuff and get a head start on residency reading. Maudsley's prescribing guide is a good start or Stahl's Essential Psychopharm if you're more into the molecular/neurochemical aspect of things.
For psychotherapy, Beck(s) and Linehan are the way to go for CBT/DBT. Judith Beck's most recent edition of CBT: Basics and Beyond was just released this month. For psychodynamic therapy Cabaniss was recommended to me by our more therapy-focused attendings, though I haven't started reading it yet. Additionally, Gabbard has a book that summarizes the most common therapeutic modalities (supportive, psychodynamic, CBT, a few others) pretty well. May be a good place to start if you're really interested in doing psychotherapy but don't want to go down a rabbit hole for a specific modality.
Note, I have not read most of those psychotherapy books, but they have been recommended to me by our psychology staff and/or therapy-oriented psychiatrists I've talked to. Others may have better suggestions, which I'd also be interested in hearing.