If you were a recruiter, which secondary language of an individual is more preferred to enlist?

Arabic, by far.
I would point out that what is important in the military is the ability to read, understand, and speak the language. A semester's worth wouldn't get you very far.

Many Army billets offer additional training and a few offer Foreign Language Proficiency Bonuses. If you can test out at a high enough evaluation on the DLPT, it is well worth your while.

Any foreign language that is spoken fluently is a bonus. wouldnt matter to me what the language is

It is only relevant if you are 100% fluent- speaking, reading, and writing, and can pass an oral and written exam administered by a native speaker employed by the Defense Language Institute (DLI). Otherwise, if you are seeking to enlist for a linguist MOS, you have to pass the Defense Language Aptitude Battery (DLAB) to determine if you are eligible for language training at the DLI. Your college courses may help you get a better score on the DLAB, but it alone has no bearing on what you are qualified to enlist for.