It depends on your goals:
If you want to just "get by", take the easiest one. That is probably the one you already know the most about already. Safe. Boring.
If you want to "become as smart as possible", take the hardest one. Unsafe. Live on the edge.
If you want to just get employed in the future, take the most practical one. Hmmm. Looks good on the resume.
If you yearn for (yet) higher education, take the most theoretical one. The admissions committee will love it.
If they all seem about the same, roll a die.
If you want to get lost in the crowd, take the most popular one. No one will notice me.
If you want some individual attention and a relationship with the faculty, take the least popular one. The prof will be able to help me understand things.
You could ask advice from one or more of the instructors, explaining to them your long term goals and seeing how the course contributes to it.
Any of these three courses could be hard or easy, theoretical or not, depending on the teacher and institution, so I won't make more specific suggestions.
Whichever you choose, work hard, think deep, live long, prosper.
If anyone thinks this is snarky or intended to be humorous, I'd suggest you reconsider. At many points in my life I specifically chose the harder path and have never regretted it. At other times I just went along with the flow and was sorry. But choosing according to my goals turned out to be pretty optimal.