For me personally, trams are right up there. Aside from the main issue of sharing the roads instead of having a dedicated line, they really make it easy to get from one part of a city to another, especially for wheelchair users. They’re usually as frequent as buses, but much faster. The stations are much more attractive compared to bus stops (on newer systems), and can really make an area feel much nicer IMO.
For those that have a bike, suburban and inter city rail is a strong second. The speed and ease of last mile mobility is what appeals to me the most. Recently took my bike across the country to my home city and it ended up being much faster than driving (by almost an hour) - the multimodal commute was pretty hefty, but lots of fun nonetheless.
Riding a bike doesn’t necessarily mean owning a bike.
Places like Toronto or London have bicycle sharing programs where for a small monthly fee you can go to one of many stations around the city, pick a bike and leave it at any of the stations near to your destination. The maintenance staff ensures that all stations have some bikes available and that the bikes remain in working condition.