Eh, this page is going to have a lot added to it n the future, but for now I'm just listing musics I know off the top of my head. This is musics from the original Japanese version, mind you.

Digimon Adventure
-Opening
Butterfly
-Ending
-Evolution Themes
Brave Heart
-Character Themes
-BGMs

Digimon Adventure 02
-Opening
Target
-Ending
-Evolution Themes
Break Up
Beat Hit
-Character Themes
-BGMs

Digimon Tamers
-Opening
The Biggest Dreamer
-Ending
My Tomorrow
-Evolution Themes
Slash!!
One Vision
-Character Themes
-BGMs

Digimon Frontier
-Opening
FIRE!!
-Ending
Endless Tale
-Evolution Themes
With the Will
The Last Element
-Character Themes
Lucemon no Theme
Blader (Duskmon's Theme)
Seraphimon no Theme
Ophanimon no Theme
-BGMs

Digimon World 4:
Out in Japan in 2005; the US release date is at this time unknown. The only ones listed are wrong. However, the Bandai of America site is located HERE, and it will doubtless list the release date when there is one.

Digimon Rumble Arena 2:
Out in Japan now, the Bandai of American site is HERE, I have HEARD September 7th as a release date, but I am unsure of it's veracity.

The UK Digimon DVDs and the third Tamers manga volume should also be out this month.