Which champions actually need a skin?

There's always a new skin concept here on the forum or there on the reddit and while annieMain3000 can suggest as many skins as he wants, the fact remains she doesn't need one (she has 9 skins if I'm correct). So I was thinking: which champions actually do need a skin? I did some digging on the lol wiki and have produced a list of the champions I deem to be in the most dire need of a new skin. Note: no champion released this year thus far is included due to no having been around long enough.

Here's a link to all my number if you want a look, otherwise the summary is just below.

High priority skins: To be applicable for a high priority skin, the champion must either have a very small number of skins, a very low available/ unavailable skin ratio and/or no "high quality" skins (unique particle effect changes) or few "good" skins. Obviously some champs won't be helped for a while. For example and who are getting reworks eventually or who despite having a horrific available/ unavailable ratio, got a full visual rework recently.

Low priority skins: To be applicable for a low priority skin, the champion might have quite a few skins but either have no "high quality" skin or very few decent skins under their belt.

Fun fact time: Holds the record for the longest time since his last skin release (22/07/2011)[dd/mm/yyyy) Has the most skins in the game at 10 Has the lowest available/ unavailable ratio at 0.4 Has the lowest skins/ lifetime ratio at 0.57

Disclaimer: Some of the unavailable stats may be wrong due to inconsistencies on the wiki, but I believe not enough to discredit my conclusions. My "worthwhile" stat on the full table is obviously my personal preference, but considering I +1 for each "high quality" skin (because they're usually good) it shouldn't have effected my conclusions too much.