This is in chronological order based on when it debuted on each episode.
Geogreymon - EP 1
Sunflowmon - EP 2
Gaogamon - EP 3
Rizegreymon - EP 13
Peckmon - EP 14
Machgaogamon - EP 15
Lilamon - EP 17
Gawappamon - EP 18
Knightchessmon - EP 21
Crowmon - EP 25
Chirinmon - EP 27
Shinegreymon - EP 29
Miragegaogamon - EP 29
Rosemon - EP 29
Rookchessmon - EP 36
Bishopchessmon - EP 36
Ravemon - EP 37
Shinegreymon (Burst Mode) - EP 38
Kentaurosmon - EP 40, DNA Charge at EP 41
Shawjamon - EP 42
Miragegaogamon (Burst Mode) - EP 42
Ravemon (Burst Mode) - EP 43
Rosemon (Burst Mode) - EP 43
Bancholeomon (Burst Mode) - EP 46