Blackjack is a BASIC version of Blackjack, that has some pretty good animations (sliding your chips in, the dealer throws slightly animated cards, and his eyes shift back and forth, ala the Intellivision version of Blackjack, which it appears to be loosely based on). It allows for up to 4 players (although each player takes their turn against the dealer; it's not simultaneous play against everyone at once). The sound, for BASIC, isn't too bad either. I am not sure if this was a freeware release back in the day, or if it was a commercial release.
Title: Blackjack
Author: Steve Kincade
Publisher: Kincade Computer Software
Released: 1983
Requires: Color Computer 1/2/3, 32K RAM, Extended BASIC, tape or disk, joystick optional.