It was a while ago (2002 I think) and it was a strange holiday as I went with my ex from uni when we knew we were going to split up.
We got a really cheap late allocation on arrival package deal from teletext and ended up in Tsilivi (we were hoping for Alykes or Alikanas). I didn't like the resort as it was all English, egg and Chips and Big Brother on the big screens in the bars every evening

The rest of the Island was really nice though. I enjoyed Zakynthos town and due to the shitness of the resort we popped over to the mainland and saw Olympia amongst other trips. I've got good memories of meal somewhere right up at the top of a Zakynthos mountain with spectacular views.
f you go to Zakynthos don't stay in Tsilivi!
I've heard great things about Skiathos from every one who's been there. I mst try it some time