Are there folks here who take meditation seriously? Do you recommend any specific meditation course/exercise? Preferably something that has proven benefits?

There are many meditation courses available online but all of them make claims about their techniques, the efficacy of which we cannot verify independently from other sources. They could as well be placebo! I am looking for reliable courses/exercises that are proven to have positive benefits.

The positive benefits could be include any positive benefit (ranging from something like better clarity of thinking to something like better digestion). I am keeping the definition of "positive benefit" open to interpretation so that we can get a variety of responses under this thread.