Off the top of my head I have to say Carver and Bloody Mary from Telltale's Walking Dead and Wolf Among Us respectively. Both excels in making you hate the character so much you're just counting down the hours to their eventual demise.
I'm having trouble thinking of anyone who falls on the worst side, so I'll give a blanket answer of forgettable.
As simple as the game was Galleon was one of the best sympathetic villains in the genre, from Lunar
Least enjoyed villains are any ambiguous super evil entity of plot convenience. Sometimes they work but rarely and it's usually super lazy writing. Unless you're truly going for ancient cthulu monster. Which they rarely are
Ugh I know I'm going to forget some great ones but okay, let's try:
Favourites:
Albedo (Xenosaga), most Xenogears villains, Orgulla (Xenosaga II, although they should/could have done much more with her), Margulis (Xenosaga), Pellegri (Xenosaga)