Mine is Giana Sisters.
Wizard of Wor.
Space Taxi (when it doesn’t crash)
Space Taxi is such a brutally hard game - but fair, and incredibly good.
Ultima IV
Space Rogue
Probably Paradroid. For pure nostalgia, Pool of Radiance, which me and a buddy played through over Christmas vacation back in 1988.
Spellbound! The music was amazing.
deleted by creator
Sword of Fargoal
Gridrunner on the 64 is probably the first favourite gamer I ever had.
F19 stealth fighter
Archon.
Cisco Heat
Gateway to Apshai
Not many have heard of it probably, but: Newcomer.
It was developed by a Hungarian team, but as far as I know there is an English version. It’s an RPG in which you move around like in Doom (but you can only turn 90 degrees). Due to the limitations of the C64, you can only see your enemies as splash art before the fight (which is character based), and it involves a lot of disk swapping (it came out on a whopping FIVE floppies!). But it’s a huge game: countless characters, conversations, fights, items to run into, and you can proceed by talking to the right people, using the right items, mentioning the right topics (sometimes you can type in key words).