My many @Computer contexts
I am in the same boat as you are. All my work is at computer and I always have internet connection. I manage my @email list through my email, so I do not need to put it on the lists, usually. I have been struggling with contexts for years and finally settled on basic principles.
Here are my lists that I found useful.
1. @inAnalytics, @inAdwords etc. I do work for many clients. Often I have to log into special tools and programs to check or run reports, etc. When I am in there, I look at my list and do all tasks associated with that tool. This works only if you have many "disjointed" tasks from many projects, but require logged in access to the tool.
2. By time - @5min, @15min, etc. These are tasks that I have to do on the computer. I have so many of them, that it helps to split them by approximate time it will take me to do them. If I need a break from analysis or coding, I look at my tasks that take 5 min and pick one that does not require mental energy. After I am done, I am back to my project.
3. @calendar. Often I am making appointments, consultations, and conference calls. I need to see my calendar that I can easily modify, send meeting invitations to people, etc. I have to be in front of my computer with Google Calendar open to complete those tasks. Hence, the context.
I think, my biggest break-through was when I heard Kelly say that it is OK to change contexts. The "default" list did not fit my work pattern and now that my mind has been liberated from the concept of "set in stone contexts", I change them around often and it works well.
I don't have @computer at all
Since I will have a computer whether I'm at home or at work, I don't use that as a context at all. I do have @home which includes computer tasks I can only do at home (e.g., my game development software),two @work contexts (one for "work" and one for admin/professional development type stuff) and @PersonalAnywhere which is where I'll put computer tasks I can do anywhere (at work, at home, on my mobile) For example, a lot of those are things I want to surf online.
I agree with the others that you should create and delete contexts as they fit your needs. Try them out for a few weeks - make a note on your weekly review checklist to think about how the contexts worked and change them accordingly.