Well, my favourite at the minute is paramesotriton hongkongensis, partly because of their behaviour,,, they seem to have a relationship. Sometimes they nuzzle each other and seem to be interacting, other times one chaces the other and might take a snap at the leg, but usually the other one knows whats going to happen and escapes in the nick of time. Also they use the tank fully and enjoy the foilage. I also like their eyes.
Cynops orientalis,, because they are just cute and I like how they hook onto plants with their tail.
Triturus carnifex because it is lord of the pond, and a protected species in England, our claim to fame. People are always suprised to hear that these creatures live locally. One day, when I have a garden I am will attempt to establish a breeding collony of them (legally of course).
Lisotriton Vulgaris bring with them the most nostalgia, as I have always been into them even before I treated it like a proper hobby or knew about other newts, and they are quite impressive still.
I want to look more into the following:
cynops ensicauda,
paramesotriton laoensis
Triturus marmoratus
I also find paddletails to be unique and worth looking into. Aggressive and territorial I hear..