What Pokemon games can trade to each other like can sapphire trade with yellow?

You can trade red, blue, and yellow with each other, and with gold, silver, and crystal once you have the ability to use the time machine trader (trades older pokemon with older moves/items). You can trade these games to ruby/sapphire/emerald with no problem up to my knowledge.

FireRed and LeafGreen can only trade to each other, and ruby/sapphire ONCE the Elite four are beaten and you retrieve the gems for Celio on the Sevii Islands.

You can only trade one way from ruby/sapphire/emerald to Diamond/Pearl.

Hope this helps!