I am afraid I did not play the Codex top 5 in my formative years so I don't really have those magic memories of them - yet.
Larn. Spent a lot of time playing this one when I was supposed to be learning stuff. I learned about Rogue games and I love them. Random, random, random. New game every time. Love it.
BT1. Not the crappy PC version. I played with nice colors. The graphics for each monster still ingrained in my memory. Love the sound of the healing temples. Played it again recently. Still magnificent, efficient Blob.
Dungeon Master. I upgraded to play this game. Unsurpassed in its perfection.
Morrowind. Like nothing else ever seen. Exploration was fantastic. Really interesting story line. Levitation. Where are those damn dwarves?
Ultima IV. I want to be the avatar as I embody all the virtues, one day. Unique game where you don't kill everything.
System Shock 2. I LOVE IT SO MUCH. Monkeys. Crazy zombie creatures. Mid wives. Stories. SHODAN. Back story.
Ultima Underworld. Poke Doom retards in the eye. This game was 10,000 better. Great story, exploration, puzzles.
Football Manager 2013
Freelancer + Crossfire. Was member of online community for a while. Even met one guy in real life.
Skyrim. Let me do what I want. Chop some wood. Pick some flowers. Kill a dragon. Become a werewolf. Join 15 opposing groups at the same time?