If you and the rest of your group want to taste wine at multiple vineyards, taking a private or small group tour, or cycling between vineyards, is the best way to get around.
If you like the freedom of picking out which vineyards you want to visit, and how long you get to stay at each of them, either self-drive or cycle between the vineyards.
If you want to eliminate the hassles of driving, parking, deciding which cellar doors to visit, and how to come up with a schedule, a guided tour is your best option.