#AltDevBlogADay - Recently brought to life by Insomniac's Mike Acton and some other guys (/girls?). It's got way more contributors than makes sense listing here.
It covers a wide range of topics, with the only common denominator being Game Development - be it design, programming or management. It's mainly there to encourage all contributors to post more often with one blog being published every day. Most of the contributors are on Twitter and share their credentials, so it should be possible to have some fruitful discussions on certain topics in case someone is interested.
Since it covers a potentially infinitely wide range of topics, singling out a representative one is pretty much impossible.