Dangerous Dave - From 2 old PC games, Dangerous Dave 1 & 2.
Darkman - from the Darkman NES game
Darth Vader - From the Star Wars games 0]
Dick Tracy - from Dick Tracy games
Dino - from The Flintstones games
Dirty Harry - from the Dirty Harry NES game
Don Flamenco - from Punch-Out!!
Donatello - from the TMNT games
Dragon Chan - from Super Punch-Out!!
Duck - from Duck Hunt :lol

lah, I don't if he was mentioned with the C ones: Commander Keen? (Even got one A: Averell Dalton, from Lucky Luke)