What's the preferred approach for a passenger jet?
I'll give the answer from an ATC perspective. A visual approach is the most preferred approach, since we can get aircraft to follow each other, and don't have to worry as greatly about aircraft getting too close. The rules say we can compress under certain conditions to 2.5 miles on ILS or radar separation approaches, but timing wise, for the runway to be clear, you can often need less separation between aircraft to maximize its usage. With the visual approach, you're vectoring to keep aircraft closer so they can see each other and follow in closely to each other to the runway.

In most ATC facilities, the Tower decides what runway to use, and the approach control calls the type of approach generally on offer(this can vary depending on facilities and how they agree to run things). A pilot can always request a different approach... they might be delayed, sometimes significantly if they insist on something way out of the loop.