How to get to the Grand Bazaar in Istanbul by public transport?

For a route with no annoying transfers: take the metro to Vezneciler station, walk down to the nearby tram stop (there's a decent currency exchange there), then ride the tram straight to the Grand Bazaar.

From the airport, take the Havaist bus route #16 — it departs on a fixed schedule rather than waiting to fill up. Daytime departures are roughly every 30 minutes, evening ones about once an hour.

An alternative is the metro, but it requires a transfer with a fairly long walk between stations, so it's not always faster than the bus.

If you're traveling late in the evening, note the metro is still running at 9pm — some travelers prefer it over the express train because of its schedule at that hour.