Unchained Alistar - get it rare? cause hes an uncooked hamburger with heals.

That being said a ton of legacy skins:

Masquerade Evelynn
Hextech Sion
Bager Teemo
Judgement Kayle
Oh and Scorpion Shen whatever it's called

Those are prob my favs out of the list

Black Alistar?

Guqin Sona and Frozen Shen.

Feral Warwick
Frozen Shen
Toy Soldier Gangplank
Swamp Master Kennen

If I had to guess, I would say that the rarest skin is Rusted Blitzcrank. I only know 1 person who has it and have never seen it from anyone else in over 3k games.

I joined too late to have any real legacy skins. I do however own Magnificent Twisted Fate.

Rarest, as in I never see it?
Molten Rammus.

Rarest as in I shouldn't see it?
PAX Sivir.

Safari Caitlyn. ._.

Silent Night Sona.

<3