I don't hate Emma, though it may seem like I do from my previous answers. I just find her a little annoying sometimes. Same with Rachel.
I like Terri and Quinn because I think they are very interesting characters. Terri is really funny and while a little crazy, Emma is completely OCD which is a bit crazy too, just in a different way. Rachel is also a little crazy and yeah Quinn's been mean before, but look at the environment she was raised in. I think that there is potential growth with Quinn and that makes me really interested in her.
I also like Puck when perhaps we're "supposed to" like Finn.
The bottom line is that people are different. If we all had the same opinions there'd be no discussion. And then there may be no need for fanpop.
Well the thing is that we are talking about TV characters, not real people that we have to meet face to face.
If I would meet someone like Terri in real life, I'm sure I would love to punch her nose, but, watching her in a show, it's pretty funny to see how stupid, shallow and crazy she is.
With the logic that you're using, we should all be hating Sue, but she's clearly one of the best characters of the show, if not THE best one.
I guess we just love to watch what we consider to be the most interesting and fun stuff, and with the best stories and dialogues.