Malta's bus system is an attraction in its own right. The backbone of public transportation in Malta is a fleet of dolled-up old vehicles from every corner of the globe. No bus in the system--or even on a given route--is exactly like any other: the drivers have a lot of freedom to customize their rides (within the basic red-white-orange color scheme), and most interiors feature an elaborate collection of photos, devotional images, slogans, and more.
And the hub of whole system is a zany hypertrophied roundabout at the gates of Valletta with a bizarre fountain full of bronze mermen in the middle. Bipedal mermen. (You figure that one out!)
Occasionally, the drivers can be rude, and from time to time their driving habits cross the thin line between "reckless" and "insane," but on the whole, the Maltese buses are a must. They cover the whole island, they're cheap (especially with a multi-day pass), and they're much better than trying to navigate Malta's roads on your own!