Strategy/Ops:
• The Innovator's Dilemma - Clay Christensen
• The Toyota Way - Jeffrey Liker
• The Beer Game - duh :-)
Leadership:
• High Output Management - Andy Grove
• The Hard Thing About Hard Things - Ben Horowitz
• Love is the Killer App - Tim Sanders
GTM:
• Start With Why (Tedx Talk)
• Benefit ladders (Human Centered Design exercise good for product AND positioning)
• Everything on Kellblog
• Everything from Andy Raskin (especially "the Greatest Sales Deck I've Ever Seen")