It's so hard to pick a Top 10. I spent so much time playing other great Legacy and Home brew games on the Coleco too.
Legacy:
Centipede
Donkey Kong
Donkey Kong Jr.
Gorf
Q-bert
Root Beer Tapper
Smurf
Space Panic
Venture
Zaxxon
If I could add five more..
Frogger
Mr. Do!
Pepper II
Popeye
Spy Hunter
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Home brew:
Asteroids
Collectorvision Club Second Years Secret Game
Deep Dungeon Adventure
DKA
Joust
Mario Bros
Missile Command
Sydney Hunter
Vanguard
Wizard of Wor
If I could add five more..
Battle of Hoth
Ghost
Prisoner of War
R-Type
Risky Rick