Desk research against primary sources, with the issuing authority linked where a page states an official fee, rule or deadline.
The honest way to choose is to work backwards from what you will actually be doing most days, not from a ranked list: a trip built around the beach and nightlife points to Marina or JBR, one built around sightseeing points to Downtown, and a trip on a tight budget with an interest in heritage points to Bur Dubai over either. Business Bay and Palm Jumeirah suit narrower briefs — central value, or resort seclusion — and are worth it only if that specific brief matches your trip.
The metro check in the common mistake is really a proxy for a bigger question: how much of each day you lose to transfers between where you sleep and where you spend your time. A slightly pricier hotel within walking distance of a metro station or your main activity usually beats a cheaper one that adds a taxi ride to every plan, once you count the time as well as the fare.