The phrase 'I strongly recommend' is a perfectly correct and usable phrase in written English. It is used when you want to express that something is highly desirable, or that it should be done. For example: "I strongly recommend that you visit the museum while you're in town.".
I strongly recommend it.
I strongly recommend this.
I strongly recommend her.
I strongly recommend George Prevedourakis.
I strongly recommend addressing this question.
I strongly recommend you hop in.
Further, I strongly recommend installing Secunia's Personal Software Inspector.
Being a terminologist, I care about word choice. Ludwig simply helps me pick the best words for any translation. Five stars!
Maria Pia Montoro
Terminologist and Q/A Analyst @ Translation Centre for the Bodies of the European Union