Chansey, Onix, Alakazam, Golem, Gengar, Butterfree, Magikarp, Snorlax, Heracross, Gardenvoir, Sheninja, Aggron
Chansey and Onix are oddballs, though yeah, true that they have history in NR and board tourneys, and they are pretty well known for what they can do (Chansey laughs at magic, vaguely mocks ITD, dies to physicals, Onix laughs at physicals that don't hit weakness, dies to anything else)
Covered Zam/Golem/Gengar/Butterfree/Magikarp.
Snorlax...could go either way. On one hand, he's pretty straightfoward; slow as hell, buffs, wins fights of attrition, has Rest, etc. You fight 2 of them and you see plenty of what he's capable of just trying to catch him. On the other hand...meh, something just feels off with him.
Heracross my one issue is that he's very much a competitive thing; yeah, he translates to some degree in the DL (Physical Slugger), but a lot of his DL worth is not seen in game since most of his good stuff is either TM or High LEvel (Mega Horn comes to mind.) Though, just seeing "Heracross" would make people think "Big physical damage dealing Bug" so I guess he's straight forward enough, and he DOES have one of his trademark competitive attacks (Reversal) in the DL so yeah, probably about as good as you'll get out of a generic Gen 2er.
Sheddy = No. He's an OB Ghost; there's really no place he can be ranked. he performs equally good in Godlike as he does in Light. Again, its a Pokemon who UNQUETSONABLY defeats Orlandu and UNQUESTIONABLY loses to Malak. The only thing that made him stand out is how unique he is. I dunno; don't feel he should be ranked cause there are other Gen 3er's who I feel deserve to be in over him.
Garde...on one hand, yeah, commonly used and interesting (Calm Mind and what not), but...eh, does feel a tad redundant when we are ranking Zam alongside it. Garde really was just a gen 3 alternative to Zam in game, who had the niche of "No Trade evo required", though, offset by how Kadabra >>> Kirlia.
Aggron...feels like the Garde scenario, but compared to Golem. Yeah, he's got differences enough to stand out, but don't feel he's quite justified enough if that makes sense?