Shabbat is probably the time when Safed's uniqueness is displayed the most. First of all, we have 3 Carlebach synagogues -- services which involve a lot of dancing and singing -- which is a significant number for a city of our size. All of these synagogues, by the way, are packed to the gills on Shabbat, especially on Friday nights when it's hard to squeeze in.
Another aspect of the unique character of Safed has to do with sharing meals. It's very common for people to open their homes to complete strangers for Shabbat/holiday meals. I often invite people who are staying in my guestroom and am asked by a couple of hospitality groups in the city to host (I've been told that I'm the only single person that hosts these strangers, which is a compliment, especially since I'm not the greatest cook in the world -- I think that it's because I always try to mix the guests with locals which makes for a friendly mix.
And then, there are people who just feel free to say "I'd love a Shabbat meal y'all. Who has a few extra spaces at their table?" That doesn't happen in very many places and it attests to the welcoming character of this town. I've heard so many people talk about how lonely they are in their cities on Shabbat because they're never invited out or would never think of organizing a Shabbat meal themselves.