I like a sparky interview candidate. I have said this on here before and got an absolute pasting for it, but the worst candidates (and I interview a lot) are those who want to get back to work after being a SAHM for a number of years. The vast majority haven't done any background research on the job/place of work and hugely lack in self confidence. I wanted to shake one woman, who, when asked why she wanted the job (an admin one) said rather pathetically "I thought I could probably manage to do it." Pre kids she had managed a chain of about ten supermarkets.
I also like a challenging question for the interviewer. One asked us what success would look like in the job, which I thought was quite good. The questions I hate are ones about leave, hours, pay (all in the job ad, and more appropriate for HR) and asking if they can work from home (yes, but not all week). I am also pretty brutal in my feedback and take time to do it - I think if you are told constructively where you went wrong, and where you performed well, you will do a lot better in future interviews.
Worst reply to a question was from an internal candidate. We do competence based interviews, and tell them what the competences will be. Me: "I'm now going to ask you a question about strategic thinking." Candidate: "I don't do strategic thinking in my job." Me: "Well have a crack at the question anyway. Everyone does strategic thinking, it's just thinking more widely and about other related issues." Candidate: "I've just told you I don't do it." Pushed back chair and left the room.
We also ask the receptionist for her views. If anyone is rude to her, that is a complete no no for me.