Which is easier, having a normal job interview or a job interview via Skype?

Both have their Pros and Cons. I would prefer a Skype one as it provides additional flexibility.

Both are equal according to the current trend.  It is now adays, the convenience matters most.

I would always recommend a face to face interview as an interview involves personal interaction. Skype interview is more impersonal & does not show certain important aspects like body language, certain mannerisms, creation of a first good impression in the way a candidate enters the interviewers office etc. As a candidate you can gauge the reactions of the interviewer on your answers & get a fair idea of how the interview is progressing.

I believe a face to face interview is always better than a Skype round if the circumstances allow for it.

Face to Face helps the two people to discuss in detail regarding the profile, in the beginning the interviewee may feel a little uncomfortable but eventually face to face is the best way to break the ice.