A generic list of what i know is out in the UK and USA in relation to Digimon DVDs

UK DVDs / Videos
Videos/VHS:
Volume 1: S1 Epi's 1-3, Volume 2: S1 Epi's 4-6, Volume 3: S1 Epi 7-9, Volume 4: Epi 10-12, Volume 5: Epi 13-15 Volume 6: S2 Epi's 1-3, Volume 7: S3 Epi's 1-4, Volume 8: S3 Epi 14-16, Digimon the Movie (Special Edition + Normal Edition + an ABC version)

Digimon the Movie
DVD of 5 epis (S1), DVD of 3 Epis (S1), Sub Zero Ice Punch (Voers epis 9-20 on 2 discs), DVD 3 box set (Season 1 episodes 1-14)

Now for some American Vids + DVD

Toys R Us, Best Buy (in case you want to say what stores in USA sell them). They are available through Amazon.com though, I know that, used and/or new.

USA DVDs / Videos
DVDs:
Digimon: The Movie
Digimon: Season 1 (actually, it's only episodes 1-13, and some bloopers)
Digimon Data Squad Box Set (Epis 1-13)

Videos:
Digimon Volume One (epi 1-3)
Digimon Volume Two (epi 4-6)
Digimon Volume Three (epi 7-9)

Gift Set of Volumes One to Three
Digimon--The Digidestined Child (epi 37-39)
Digimon--Battle With Piedmon (epi 50-52)

Digimon--A New Digitude (epi 1-3)
Digimon--Emperor's Last Stand (epi 19, 20, 21, and 23, if reviews are correct)
Digimon--Birth of Guilmon (epi 1-4)
Digimon--Revenge of the Digital World (epi 14-16)