In a professional context, I've been solely responsible for the coding for a wide variety of websites. Including this one! This has primarily been a matter of moving data in and out of MySQL databases, performing sanity checking on user inputs (which is sysiphean), and sometimes sending automated emails or uploading images. It is not terribly exciting.
If you'd like an example anyway, however, the most recent would be The National Farmbank, a free service allowing farmers to advertise surplus stock.
In terms of games development, my involvement with coding has been more limited, with only two major projects where I was responsible for code. The first of these, which for lack of a better name was simply called "Platformer", was a solo project, where I was responsible for everything. It turned out pretty well, all things considered.
I've also worked on a number of games in larger teams. The main example for this where I was working as a coder is The City, which, while flawed in many ways, represents a fairly respectable outcome for a first-major-project in ActionScript, developed part-time over three months from conception to completion. While the way in which the code was written was deeply unsuited to working with a team of programmers (my style defaulting to procedural unless checked at every step), valuable lessons were learned along the way about working with an art team in order to ensure the process of importing art assets is as simple and as clearly documented as possible.
I also, during development of The City, created a simple system for collecting feedback, as this would (theoretically) have helped with the design and development process. Sadly, logistical complications towards the end of development meant that we never really got the chance to act on the feedback collected.