Between Ruby and Sapphire, not counting any other group, here are the version exclusive Hoenn Pokemon:
Ruby:
Seedot, Nuzleaf, Shiftry, Zangoose, Solrock, Mawile, Groudon.
Sapphire
Lotad, Lombre, Ludicolo, Seviper, Lunatone, Sableye, Kyogre.
Which means for these two games, you don't get Seedot in Sapphire, and you don't get Sableye in Ruby.
For Emerald, these are the missing list of Hoenn Pokemon:
Meditite, Medicham, Surskit, Masquerain, Roselia, Zangoose, Lunatone.
As for Fire Red and Leaf Green, again they both have version exclusives, but between the pair of these games you can get all the Kanto set.
Fire Red has these Pokemon missing:
Sandshrew, Sandslash, Vulpix, Ninetales, Bellsprout, Weepinbell, Victreebel, Slowpoke, Slowbro, Slowking, Staryu, Starmie, Magmar, Magby, Pinsir, Azurill, Marill, Azumarill, Misdreavus, Sneasel, Remoraid, Octillery, Mantine.
Leaf Green has these Pokemon missing:
Ekans, Arbok, Oddish, Gloom, Vileplume, Bellossom, Psyduck, Golduck, Growlithe, Arcanine, Shellder, Cloyster, Electabuzz, Elekid, Scyther, Scizor, Wooper, Quagsire, Murkrow, Qwilfish, Delibird, Skarmory.
Right, now onto the GameCube games. From Colosseum, you can get only the following:
Espeon, Umbreon, Makuhita, Bayleef, Quilava, Croconaw, Misdreavus, Slugma, Noctowl, Flaaffy, Skiploom, Quagsire, Furret, Yanma, Remoraid, Mantine, Qwilfish, Dunsparce, Meditite, Swablu, Sudowoodo, Plusle, Hitmontop, Entei, Ledian, Suicune, Gligar, Sneasel, Piloswine, Stantler, Ariados, Aipom, Murkrow, Forretress, Granbull, Vibrava, Raikou, Sunflora, Delibird, Heracross, Skarmory, Miltank, Absol, Houndoom, Tropius, Metagross, Tyranitar, Smeargle, Ursaring, Shuckle, Togetic, Ho-oh.
And for Pokemon XD, the following are obtainable:
Eevee, Teddiursa, Ledyba, Poochyena, Houndour, Baltoy, Spheal, Mareep, Gulpin, Seedot, Spinarak, Numel, Shroomish, Carvanha, Delcatty, Voltorb, Makuhita, Vulpix, Duskull, Ralts, Mawile, Snorunt, Pineco, Natu, Roselia, Meowth, Swinub, Spearow, Grimer, Seel, Lunatone, Nosepass, Zangoose, Togepi, Elekid, Paras, Growlithe, Shellder, Beedrill, Pidgeotto, Tangela, Butterfree, Magneton, Venomoth, Weepinbell, Arbok, Primeape, Hypno, Golduck, Sableye, Raticate, Dodrio, Farfetch'd, Altaria, Kangaskhan, Banette, Magmar, Pinsir, Magcargo, Rapidash, Hitmonlee, Hitmonchan, Lickitung, Scyther, Chansey, Solrock, Starmie, Electabuzz, Swellow, Snorlax, Poliwrath, Mr Mime, Dugtrio, Manectric, Salamence, Marowak, Lapras, Lugia, Articuno, Zapdos, Moltres, Tauros, Rhydon, Exeggutor, Dragonite, Sandshrew, Gligar, Trapinch, Hoppip, Phanpy, Surskit, Aron, Zubat, Wooper, Meditite, Larvitar, Shuckle, Cyndaquil, Totodile, Chikorita.
Well, that took it's time. Hope this helps.
