In any "you-can-kill-knock-out-or-sneak" game where you can't actually sneak without being seen without the quickload key. Deus Ex did this, too many outright firefights and cameras around corners (they did try, though).
Also, a "run-and-gun-or-stealth" game with ONLY ONE usable stealth route. Give me options!
Lastly, Real-Time RPGs that claim you can sneak past enemies to continue, and don't reward you for it! And then force you to fight later, about ten levels down from what you should be! (Specifically, I'm thinking Geneforge, kudos to anyone who knows what that is.)