Recommendations

Hope the lists below will be useful for you.

on (ui/ux)design & research:

Don’t Make Me Think, Revisited: A Common Sense Approach to Web Usability | by Steve Krug
Atomic Design | by Brad Frost
Refactoring UI | by Adam Wathan, Steve Schoger
UX Collective
Rocket Surgery Made Easy: The Do-It-Yourself Guide to Finding and Fixing Usability Problems | by Steve Krug
The business value of design | McKinsey Quarterly
Service Design: From Insight to Implementation | by Andy Polaine, Lavrans Løvlie, Ben Reason
The User Experience Team of One: A Research and Design Survival Guide |by Leah Buley
Universal Methods of Design: 100 Ways to Research Complex Problems, Develop Innovative Ideas, and Design Effective Solutions | by Bella Martin (Goodreads Author), Bruce M. Hanington
Interviewing Users: How to Uncover Compelling Insights | by Steve Portigal
How to Do Things with Words | by J.L. Austin

on games & gamification:

Anything by the Gamification Group
The Art of Game Design: A Book of Lenses | by Jesse Schell
Reality is Broken: Why Games Make Us Better and How They Can Change the World | by Jane McGonigal
Homo Ludens: A Study of the Play Element in Culture | by Johan Huizinga
The Grasshopper: Games, Life and Utopia |by Bernard Suits
Flow: The Psychology of Optimal Experience | by Mihaly Csikszentmihalyi
Actionable Gamification: Beyond Points, Badges, and Leaderboards | by Yu-kai Chou
Rules of Play: Game Design Fundamentals | by Katie Salen, Eric Zimmerman
Nudge: Improving Decisions About Health, Wealth, and Happiness | by Richard H. Thaler, Cass R. Sunstein
Masters of Doom: How Two Guys Created an Empire and Transformed Pop Culture | by David Kushner

Service Design Turku (A small but powerful group of people with great events from Turku)
SDN
IGDA Finland
Global Game Jam