Since I never had many consoles, mostly micro's instead, I have a shorter list:
1) Impossible Mission, C64
2) Loderunner, C64
3) Raid on Bungeling Bay, C64
4) Zork Zero, C128
5) B17 Bomber, Intellivision
6) Pirates!, C64
7) Gunship, C64
8) Portal, C64 (A classic Activision title that seems to have a bug in it, you can't finish/complete this game)
9) Bards Tale 1 & 2 (A Tie), C64
@Burseg, what Tape drive
My dad had one for about a week then bought a 1541 for this very reason
Myself I bought one with my first C64 system.
EDIT: I have to make a change to my list I really have to add this title after some self-debating on the drive home from work.