Earliest game I remember loving and being utterly terrified by was Hunt the Wumpus on the TI 99/4a . Close 2nd to that would be Parsec with the speech module
"Good shot, pilot"
Happy memories.
My first purchase was Raptor: Call of the Shadows
Bought it as I loved playing it back when it was one of the few games with native Gravis UItrasound support.