Lanzarote for me, absolutely loved it.
The locals simply accept cyclists, I presume as some pro teams train on the island in the winter, and of course Lanzarote also hosts one of the most prestigious Iron Man events as well. As a result you are given loads of room by motorists the like of which I've never experienced before.
The main roads all put UK roads to shame, they're like glass in comparison.
The only downsides, (there has to be some right?), are the almost relentless wind and the volcanic aggregate they use for all sorts of purposes. Therefore I had more punctures in two weeks that I normally have in two years, but never the less, I'd go back tomorrow.