Posted: June 21, 2014
Short version: You need zero programming experience to build games in GameMaker. But it also has an object-oriented language you can use for advanced programming.
The year was 2004, and I was in junior high study hall. I stumbled across a demo of GameMaker 5.3, and downloaded it to my trusty floppy disk. A few dumb projects later, I convinced my dad to cough up the $15 for the Pro edition.
For the summer and for some time beyond, I busied myself with making dumb little games with no real point. I did the free upgrade to 6.0 soon after. After an attempt at a Megaman clone and a goofy Star Wars game, I lost interest. I'd kick around an idea for awhile, but lacked the initiative to complete anything.
Flash forward to 2011. I was finishing up a degree in Computer Programming and needed to log 40+ hours on an independant programming project to satisfy my intership requirements. Despite all of the mainstream programming languages I already had been required to choke down in my studies, I decided to teach myself GML - the scripting behind GameMaker. I learned that YoYo Games had made many changes to the original interface that Mark Overmars had engineered, and I was skeptical. I decided to stay with my older version, and to keep away from those that had disgraced my favorite little sandbox.
After deciding to return to Indie Development as a more serious endeavor last year, I discovered YoYo Games had overhauled their entire engine and made GameMaker Studio. A little group in Scotland had taken the "fake programming" engine that no one took seriously in my college classes, and turned it into the source of many popular Steam Indie titles.
Think it's expensive to get full version and export modules to port to console and mobile? Look up the Microsoft Visual Studio Professional suite and see how reasonable GameMaker is in comparison. The newest version still is driven by GML. You can use scripting more and more as the foundation for games, but the drag-and-drop is still nice for prototyping.
If you buy it, get it on the official company site, and in addition to the standalone, they'll give you Steam keys for it within a week. They always have free versions to try and plenty of support in indie game communities.
If you have the time and the patience, Steam Greenlight may be your next stop.