Top 5 games. eh!? As Mario would say:
"Here we go!"
Deux Ex (I played the heck out of this game, starting and restarting, and always trying to get the smoothest playthrough. Plus, the voice acting!)
Hero's Quest: So You Want to be a Hero (before the lawsuit and it became Quest for Glory. I first saw this game at a Basic programming competition in 1990. I loved the RPG elements mixed with the earlier point and click adventures. It was nice that it got remasted.)
Wonderboy in Monsterland on the Sega Master System (A fun little classic that I spent a lot of hours trying to get past. I do love save states now)
Dishonoured (like Deux Ex, this game is amazing with the world, the levelling up, the powers/abilities, the stealth, the murder -- peak gaming)
Legends of Zelda (never played this as a kid as we had Sega and not Nintendo, but I found it as an adult and just feeling part of that long history is nice. Plus it isn't 1000 hours long)