All those are good.
All Pikachu trophies from 97-99 and probably beyond, as well. 1st ed base Blastoise for sure. 1st ed Chansey in 10. All the Snaps. Unikarp in 9 or 10. Masters key 10. Shadowless Zard in 10. Espeon and Umbreon gold stars in 10. Tropical mega battle. Crystal Charizard 10. 1st ed neo Lugia in 10.
Thank you for including shadowless zard 
This is a pointless exercise because itās not taking into account whether an item in a specific grade is correctly valued relative to the same item in a different grade.
Youāre operating under the premise that a card in the top 1-3% is a superior āinvestmentā to a card not in the top 1-3%. And youāre also operating under the premise that a PSA 9 GS Ray is not in the top 1-3% but that a PSA 10 GS Ray is. Based on these premises, it would be a superior decision (from an investing standpoint) to purchase a PSA 10 GS Ray ($40k) over a PSA 9 GS Ray ($8k).
This conclusion isnāt sound, though, because youāre implicitly assuming that the current price gap between the PSA 9 and 10 is reasonable. I (and many others) would argue that PSA is not competent enough at distinguishing between āmintā and āgem mintā cards to make a 5x price gap between the two reasonable. If you tasked me to invest $40k in GS Rayquazas with the sole purpose of yielding the highest ROI, I would much rather purchase 5x PSA 9s than 1x PSA 10. I think this is a reasonable instinct and one that most others on this forum would agree with. But itās an instinct that conflicts with the way youāve framed the post.
Basically, I think Pokemon is too young of a hobby to determine which cards are ābetterā investments than others. Many items are valued irrationally relative to other items. And so investing blindly in the top 1-3% of items could actually end up working out very poorly. I think the advice to ājust buy what you likeā is probably apt here.
So just to clarify , youāre saying that Investing into PSA 9 Gold Star Rayquaza would be a better ROI for the long wait game then the ROI on a PSA 10 Gold star Rayquaza ?
Either way I do agree with your assessment on this whole thing
Truly impossible to know. Historically in other categories for modern cards 10s have had a more stable price floor but you donāt really know. A PSA 1 Ray could have the best ROI moving forward, but thatās certainly not investment grade like OP was asking for
The natural instinct or desire of the owner must FIRST be to OWN the thing, and keep it when value changes. yeah?
So the top cards must be things that have higher values in this criteria.
Thatās what I personally believe, but I donāt know that for sure. All Iām saying is that there are good reasons to suspect that the 10 wonāt have a better ROI, and that the OPās model doesnāt take those into account.
I think with the price that Rayquaza is now ( especially 2 years ago lol ) ROI does make sense years down the road. So I totally agree with you
Just donāt get why some here donāt see Gold Star Rayquaza as an option at all be it PSA 9 or 10 lol
To be clear: Iām not saying that I think PSA 9 GS Ray is a good investment ā just that I think thereās good reason to suspect itās a better buy than a PSA 10 GS Ray at the current price lol. GS Ray might be a great investment, or it might not be. I have no clue. Itās certainly a top-tier card, though. And if Pokemon does well, then Iād imagine that the Ray will also do well.
greninja gold star is up there
What we are trying to determine is what is in the Top 1-3% of the hobby by the 3 criteria stated at the same time.
On the other hand, and making reference to the article, what that āinvestment gradeā meant is not which is the best investment, but the safer.
I totally agree with you on what you are saying, ROI could be much better in PSA 9 that in PSA 10 coming forward, even PSA 1 as @traineramy saidā¦ who knows.
But, not taking into account what those cards will be worth, that 1-3% is a safe place to put a limit on which cards will always be wanted by collectors. Even though the hobby colapses o main attention is in other things, like sealed product or whatever.
Lastly, I also totally agree in that the best approach is probably to buy what you likeā¦ I donāt consider my self as someone that invests in PokĆ©mon in any mannerā¦ Iām a collector and have my collection goals, that I love to chase. I canāt completely understand what this has to do with the post.
Determining the Top 1-3% of the hobby doesnāt mean that we are establishing what are the best buys, or what should people chase. These are just grails, that will probably retain value in the long run, better than other things that are not so special (doesnāt mean that will be the best performersā¦ ask Lillie lol).
Have a nice day!! 
Japanese Battle Road promos, or rather any of the event related promos which were either handed out as a participation / prize cards for the various competitions held at these events. These cards have a lot of significance and history in terms of itās distribution and there are quite few which are Japanese exclusive. They may not be the most expensive (atleast not all), but probably when a lot more people know about these promos, I can see them gaining popularity and holding value in the future.
Cheers!
I like Greninja 
! Itās one of those more affordable gold stars that is not any of the dog trio!
All of those seem solid candidates as well!
Just curious, why do you choose Chansey 1st over, for example, Venusaur?
Chansey much harder to grade!
I will have to ponder this question as I sit here in the Bury Khalifa.
Thatās true, and Blastoise sits in the middle of the two.
Blastoise is a top 1% most popular pokemon, not necessarily a hard grade
Yes, but Blastoise 10s have a lower % as, for example, Venusaur or Mewtwo.