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Personally I like Serper.
Always I read again and again of him. The Typical Patterns series.I read again and again.I also like Silman and Natalia.
My own personal preference is for Iryna Zenyuk (aka Energia) ... although Natalia Pogonina has written some very nice stuff that I liked. But I've read many more articles by Zenyuk than Pogonina, and if this were a survey situation, my vote would go to Zenyuk.
Silman for me, he writes in a really engaging fashion.
I enjoy batgirl and NimzoRoy.
Guess it depends on what you're looking for. I really appreciate batgirl for her historic perspective and I also like the analysis of her own games she posts. NimzoRoy has always excellent chess knowledge to dispense and seems to be a nice dude.
The professional article writers on this site keep all a certain standard.
Bryan Smith, without a doubt.