Oh, and in case you were wondering...
Gen 1: Red + Blue, and Yellow
Gen 2: Gold + Silver, and Crystal
Gen 3: Ruby + Sapphire, Fire Red Leaf Green (remake of Red and Blue), and Emerald
Gen 4: Diamond + Pearl, HeartGold + SoulSilver (Remake of Gold and Silver), and Platinum
Gen 5: Black + White, and Black + White 2
Yellow, Crystal, Emerald, and Platinum basically remix the original pairing of the generation, and improve them. Generally preferable to original versions.
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My Little Phineas and Ferb: Summer is Magic!
Aww, I lost to SuperNiceDog, Winner of the Rivalry Rumble Guru Contest