It has been my experience that the tram systems in different cities have completely different personalities. I lived in central Europe for a year and public transportation is much more prevalent there, and my family was without a car. We used the trams most of the time, for the scenery and the price, and I began to keep a log of what they were like. I don't have a large chunk of them here, because I was writing it in my journal while sharing a hotel room (usually) with my sister, who was 9 at the time and habitually inquisitive. However, this sampling describes what they're like well enough:

Vienna, Austria: These are, I believe, the gentlest trams in the entire world. They are also cold. At first, you don't even realize they're moving because the pace is so impossibly slow. The service is utilized by quite a few tourists, although well-meaning ones, and many, many little old ladies who may swat you if you refuse/forget to offer your seat. The trams in Vienna were never crowded, even in the most touristy areas.

Prague, Czech Republic: the entire city caters to tourists, and the trams go along with this while adding a sort of "off the beaten path" touch. If you've never been on a tram before it seems sort of wild at first, since it's crowded with tourists, gypsies, little old ladies and yapping little dogs, but I realized soon enough that it was mundane in comparison to almost everything.

Brno, Czech Republic: I lived in Brno, and so I have the transportation system imprinted in my head -- or maybe it's smashed into my head, as the cable cars always seemed ready to fly off of the tracks. Almost daily, I went from my building to the grocery store to do shopping -- by tram, it was 7 stops on the number 2, and took about five minutes. It was almost frightening at times. The traffic was quite variable but, except for "rush hour", there was generally space to sit on the trams.

Bratislava, Slovakia: I was only in Slovakia for a short time -- one day, in fact -- and only used the trams twice, however, they seemed very quiet and quite civilized. Judging by the ride from the train station to the heart of the city, I would have categorized them with the Vienna trams, were it not for our friends telling us that usually they were utilized by large groups of noisy half-drunks. I saw on the ride back that this was true, and it really is distracting from the ride as all trams are fun.

Budapest, Hungary: Like everything else in Budapest, the tram system really has character. They got us where we were going in good time, and the view was fantastic, but that's all beside the point: everyone riding the trams was either in a great mood (cheerful, calling out the windows to people they knew) or absolutely sulking (sitting quietly, buried in a newspaper and grumbling if you bumped into them accidentally.)

San Francisco, USA: (this is the trams, not the historic cable cars, which are crowded and silly.) This was my first exposure to trams anywhere outside of central Europe and I was rather surprised that they had the means to exist in the United States. They were generally either empty or full (I clarify: it usually wasn't in the middle), but pleasant, and the people who used them formed something of a network. They got us where I wanted to go and I think that other than the Brno trams (which are my favorite just because I lived there) I liked them the best.