Standard Bash with a twist:

[ /full/path/~-prefixed where possible ]
 user@short-hostname $ _

(Underscore = cursor, not part of prompt, in case that's not obvious.)

It's similar enough to the most common Bash prompt that I don't feel totally alienated on a different system but different enough to be unique / useful.

The carriage return is deliberate. Paths can often get quite long in my homedir (if not other places), even with the ~ abbreviations. I can't imagine anyone likes starting to type a command more than halfway across a screen because of a long path; this was my solution.

The spacing is deliberate too. The brackets are hard to distinguish without the spaces either side of the path. On the second line, the 1-char indent and the spaces around the obligatory $ were the layout I found most pleasing.

There are embedded colour codes, but it's designed so that it looks fine without them, just in case.

As for other configuration, I use whatever comes with the distro I'm using, especially any command-completion, etc.