After a quick Google sesrch, I found this from here:
AG stands for the Advanced Generation and DP stands for the Diamond
and Pearl series.
Episode 67 (The Pi-Kahuna), Pokemon the First Movie: Mewtwo Strikes
Back, Episode 68 (Make Room for Gloom)
Episode 105 (Charizard Chills), Pokemon the Movie 2000: The Power of
One, Episode 106 (The Pokemon Water War)
Episode 155 (The Forest Grumps), Pokemon the Movie 3: Spell of the
Unown, Episode 156 (The Psychic Sidekicks)
Episode 205 (The Kecleon Caper), Pokemon 4Ever: Celebi: Voice of the
Forest, Episode 206 (The Joy of Water Pokemon)
Episode 256 (Just Add Water), Pokemon Heroes, Episode 257 (Lapras of
Luxury
AG Episode 34 (Having a Wailord of a Time), Jirachi: Wish Maker, AG
Episode 25 (Win, Lose, or Drew!)
AG Episode 85 (Sky High Gym Battle), Destiny Deoxys, AG Episode 86
(Lights, Camerupt, Action)
AG Episode 134 (A Real Cleffa-Hanger), Lucario and the Mystery of Mew,
AG Episode 135 (Numero Uno Articuno)
AG Episode 183 (Aipom and Circumstance), Pokémon Ranger and the Temple
of the Sea, Episode 184 (Strategy Tomorrow - Comedy Tonight!)
DP Episode 39 (Steamboat WIllies), The Rise of Darkrai, DP Episode 40
(Top-Down Training)
DP Episode 86 (Arriving in Style!), Giratina and the Sky Warrior, DP
Episode 87 (The Psyduck Stops Here!)
DP Episode 135 (Beating the Bustle), Arceus and the Jewel of Life, DP
Episode 136 (Hustle and Gateway to Ruin!)
Also, you can find more information about how the Pokemon movies fit into the timeline here, here, and here.
Please refer to this relevant question: https://scifi.stackexchange.com/questions/73310/what-is-the-correct-viewing-order-for-the-pokemon-tv-series-and-movies
In addition, you can find a complete list of all the Pokemon movies here.