This outpost in the asteroid belt has very resilient locals, who seem to be able to survive, and still taunt after being burned, electrocuted, shot through and otherwise decapitated in various ways.
Hyperion and Pandora. Interesting place to go if you want to find crooks, con artists, psychos and vault hunters. Check out the one guy who totally looks like he was in Fear and Loathing in Las Vegas.
Sanctuary is pretty cool, bunch of fun people with strange habits. There are rummagers who keep trying to find something in the garbage, and people who rap metal sheets in the pattern of a train running. There seems like there was a genetic bottleneck somewhere in Sanctuary's history.
Concordia is fun, different gene pool from Sanctuary. People seem to be a lot more in touch with day to day events. Moxxi has a bar in both Sanctuary and Concordia, which tends to act as a hub to gather about all the most interesting inhabitants.
Larunda Relay, at Mercury is a nice place to visit again and again. The inhabitants are pretty calm, even the security guards. There are a bunch of syndicate headquarters at the relay, a few trees and fountains. All in all, it is a calm environment, though you never know what kind of creatures/machines/entities you can run into.
Elan Blude is funny, the location is a medieval town, but the people seem like an eclectic mix of time travelers from across the years.
Roumen and the nearby Sand Beach are pretty fun. The mobs of various colorful creatures pose with you patiently, before turning around and trying to bite your head off.