TurnipGames - Pokemon Full DVD Collection

Season 1: Indigo League - 3 dvd box sets
Season 2: Adventures in the Orange Islands - 1 dvd box set
Season 3: The Johto Journeys (no box set available, 41 episodes)
Season 4: Johto League Champions (no box set available, 52 episodes)
Season 5: Master Quests - 2 dvd box sets
Season 6: Advanced - 2 dvd box sets
Season 7: Advanced Challenge (no box set available, 52 episodes)
Season 8: Advanced Battle (no box set available, 52 episodes)
Season 9: Battle Frontier - 2 dvd box sets
Season 10: Diamond and Pearl - 3 dvd box sets
Season 11: DP Battle Dimension - 3 dvd box sets
Season 12: DP Galactic Battles - 4 dvd box sets
Season 13: Sinnoh League Victors - 3 dvd volume sets
Season 14: Black & White - 4 dvd volume sets
Season 15: BW Rival Destinies - 3 dvd volume sets
Season 16 Part 1: BW Adventures in Unova* - 1 dvd volume of 25 episodes
Season 16 Part 2: BW Adventures in Unova and Beyond* - 1 dvd box set of 20 episodes, not announced yet.
Season 17: XY - current season, no dvds. 43 episodes aired so far.

*halfway through the season the title switched to BW Adventures in Unova and Beyond.

After season 12, they stopped doing box sets. So from season 13 and on, they are all individual volumes sadly.