Yes, I did this too if possible. I got one professor who was super easy teaching American history, then to fill up my humanities and history requirements, I found him teaching Texas history another semester (yes, they do teach an entire history class about Texas, even had a few books to read for essay questions, but he would write 3 essay possibilities on the review sheet, and one of the 3 showed up on the exam). The tests were nearly identical to his review sheet, class super-easy. Then, I took his class for world geography (they moved his subjects around quite a bit) and another class called urban geography another semester. I did one of his classes each semester he taught something different once I found out how easy he was.

Can you ask around to others in your major if they have heard anything about the classes for next semester, which professors are hard, which are not? For me, this was so helpful for organic chemistry, biochemistry, and even my "B" class, Physics II (so lucky to get the B). Not that these required subjects for my major were easy, but I learned beforehand the professors I took were easier than the profs offered that semester.

However, I went to an extremely large college (Texas A&M, main campus), so I had lots of opportunities for different professors even for required courses. I also needed 4 semesters of PE to graduate; those you could take on pass/fail, but only got 1 credit for, so I took 3 semesters of badminton, one of self-defense, and later to have the hours I needed, badminton again.

Seminar classes if they fit into your schedule are easier too, but they also tend to give 1 credit. Most of those were graded by attendance though there was one each student got a topic to present (no tests though). I did a poster on pheromones, a topic that turned out to be more interesting than I thought when I found that was my presentation topic. Most of the seminars you could also take on pass/fail. Mostly they looked at attendance and if you did your part (such as the presentation), if you paid attention in the poster class, there were large seminars too where a scientist would come and talk about their research, new developments in their field of study. That one, the student advisor actually wrote down names as students in science came in or out and if she saw them seated (though those seminars were huge, hard to see if a student attended or not, so I always made sure the advisor had my name on her list when leaving), and you had to have attended a certain number of times for the credit.

Oh, and my psychology (just basic) course offered partial credit the more psychology research you participated in (by the psych grad students), even getting out of exams. It was stuff like hearing words, doing a page of math problems, then writing the words you remembered. One I did was pictures of how attractive each face I saw projected. Another had one group shown good/happy pictures (kittens, things like that), the other negative/scary things (WWII atomic bomb & aftermath, scary bugs, monsters, etc.) then you had to rate your feelings right after seeing these things (I was in the bad image group). So see if there are courses that my help or give extra credit to your main grade if you participate in graduate research.