Mmm, I don't exactly think it's fair to include Adventure 01, 02, and Tri as a single Season. Each one has their own theme, so it feels like cheating to include them together, as it gains the fans of all three Season together.
Overall though, Tamers has always been the more popular Season, due to its more serious tone and more mature themes. Adventure only has the lead (currently) because, as I said, it's including 3 Seasons in one. Separate them the way you should have, and we can see that Tamers wins in popularity almost easily.
DigimonWiki
