The general area is for stuff that is useful such as algorithms, mathematics and podcasts.
Red Blob Games
Resources for understanding path-finding, AI, tiles, hexagons, game design, scripting, objects, adventures and economics.
Good range of tutorials covering Unity, XNA, HTML5 and DirectX.
Lou’s Pseudo 3d Page
Ever wanted to make a Pseudo 3D game similar to OutRun? This is the place to start.
Covers a couple of small games such as Simon Says, Snake and Curve Fever alongside a bunch of Tower Defence tutorials.
40+ Fantastic Game Development Tutorials From Across the Web
This is basically a massive dump of tutorials covering maths, design, presentation and programming.
Toymaker is maintained lecturer at Teesside University who worked for Westwood Studios. There are a bunch of resources for learning DirectX and XNA as well as more generic information.
Game Development Stack Exchange
Worth taking a gander at when they arrive. Sometimes useful findings. If you can tolerate the Stack community you can even help out.
Open Source Game Clones
Feel like contributing to some open source game remakes or clones? Want to learn from others projects? This is a huge list of open source games written in a range of different languages. I love visiting this site just to check out what other people are doing.