Title says it all. I'm looking to get a couple and I want to hear some opinions on rare and hardly seen plecos 
In no particular order:
Luteus
Xantos
Blue Eye Pleco
Typhoon LDA105
Goldline Teles Pires L27
Titanicus L273
Those are my picks...L273 is not as rare as the others mentioned but a nice quality one is hard to find. There is alot of bland colored L273 going around.