I've played all the pokemon games, except for X/Y, OR/AS so far. Yellow/Red/Blue and Silver/Gold/Crystal are the ones i remember least because i was like 4-5? or so. Pokemon Ruby i remember clearer. I remember that i got ruby and my cousin got sapphire and we had a rivalry going on as to who got the better pokemon, who beat the game faster and stuff xD, that carried on to Diamond and Pearl, i got Diamond and he got Pearl. After those he stopped and i carried on alone, playing Platinum, HG/SS, B/W and B/W2. My most vivid and best experience tho was Diamond-Platinum. Gen 4 ftw . I played that when i was like 11-12 or so. Memories~
I would also like to add Pokemon Mystery Dungeon Explorers Of Time!! I've also loved that one too (although the chatting was a bit too long and boring), i still liked that game.