Difficult decision, I love each one, even those that are not that colourful. But if I really had to chose my favourite would be Maratus personatus. The blue mask is so special, no other peacock spider has anything like it and it goes brilliantly with the white scales on either side. I also love his little bandanna on top and the way his third pair of legs seem to clap while he courts the female. Blue is my favourite colour too and the only one I can see very well.
Second in line would probably be Maratus volans, a beautiful species, yellow is not that common among peacock spiders and it has relatively large flaps as well. It will always be special for me since it was the first peacock spider I encountered and sparked the passions that sustains me to this day.
The third one that comes to mind is Maratus tortus. Its courtship dance is like no other, extremely energetic, impossible not to fall in love it.
And one last one to round this up with ------- Maratus vespertilio. Not a colourful species but also among my favourites. To me this spider looks exceptionally cute and the male's hopping contests are unique. If you don't know what I mean watch my video Peacock Spider 3