As a public park manager, I've tested nearly every type of urban trash bin available. Through trial and error, I've found that stainless steel bins with rounded, seamless designs are by far the easiest to maintain in the long run.
The smooth surface resists graffiti better than textured materials, and most spray paint can be wiped off with standard cleaning solutions. More importantly, stainless steel doesn't rust like coated metals or crack like plastic when exposed to year-round weather changes. Look for bins with minimal seams and joints - these areas trap debris and become maintenance headaches.
I particularly recommend bins with top-openings rather than side-openings. Top-openings prevent rainwater accumulation (which creates mosquito breeding grounds and unpleasant odors) and reduce animal scavenging. The simple mechanism of a hinged lid is far easier to repair than complex pedal or sensor systems that frequently malfunction in public settings.
For high-traffic areas, consider larger capacity bins (at least 50 gallons) to reduce overflow and decrease collection frequency. While initial costs might be higher, the reduced labor hours for cleaning and repairs make stainless steel bins the most cost-effective choice over a 5-10 year period. Pair these with durable, removable liners, and you'll have a waste management system that practically maintains itself.