Recommend Me a Cool No-Download Browser Game

To recommend a great no-download game, I need to know your preferences:

Genres

• Puzzle: Logic, brain-teasers
• Action: Fast-paced, reflex-based
• Strategy: Tactical planning
• Adventure: Story-driven exploration
• Word: Crosswords, Scrabble-likes
• Sports/Arcade: Simulations or classics

Platforms

• Web browser (instant play)
• Mobile (Android/iOS web apps)
• Social media embedded games

Tell me what you enjoy, and I'll suggest specific titles you can play instantly!