I'm currently an undergraduate Computer Science student entering my fourth year at a Canadian university, planning on applying to graduate programs in Theoretical Computer Science. I'm going to be starting with school in a bit over a week, and I'm still finalizing what courses I plan on taking this coming year. At my school we typically take 5 courses per semester. I'm strongly considering taking a lighter course load (3-4 courses per semester) this year, for a number of reasons, in no particular order:
I've completed all of the requirements for my school's CS program (plus a math minor), and I only need three more courses in any area to finish my degree.
In theoretical CS, I've exhausted all of my university's undergraduate courses in the subject, as well as a couple of grad courses. This year most of my course work will consist of more grad courses in this area.
I'm hoping to spend more time on research this fall. Last year I worked on a research project with a professor, and found myself feeling like I could have gotten more out of it if I had been taking fewer courses at the time.
By taking fewer courses, I can save a few thousand dollars in tuition fees. While I can technically afford the cost of taking a full course load, it doesn't seem to make sense to pay much more than I have to, especially if I can put the money saved towards something else.
Even if I'm not taking as many courses for credit, I'm still planning to audit a few extra courses. These would mainly be outside of my primary area of focus, but where I'm still interested in learning about the material. It would also be less stressful, since I wouldn't have to worry about assignments and exams for these courses.
Overall, I have all of these reasons to justify to myself my plan to take fewer courses during my final year of undergrad. However, I was wondering how this would be seen from the perspective of a graduate admissions committee, since courses that I plan on auditing will of course not be visible on my transcript. I don't want to give off the perception that I had gotten "lazy" in my final year by taking fewer courses, if that makes sense.
It's normal for seniors to take a lighter course load in order to work on their senior research project. Most universities have a "senior project" faux course at the 400- level to indicate this. Some do not.
As far as how grad admissions will view this. As long as you can show that you weren't slacking off your senior year -- perhaps by showing your senior project results in your application dossier, or alternately asking your research supervisor to write for you -- you should be ok.
If you do feel burnt out, I would take a gap year -- either between junior and senior years -- or right after college. Grad school is a long haul.