Have you had a glance at our help page yet?
90% of what's in there is common to every Stack Exchange site. The only part unique to Seasoned Advice is the very first link, What topics can I ask about here? Even the second link, What types of questions should I avoid asking?, is common to all sites.
Of course, different sites may have different interpretations of the rules and guidelines, and that's all up to the community and its moderation. For example, Stack Overflow tends toward not allowing any subjectivity in their questions, whereas other sites, like Sci-Fi, are almost by definition going to tend toward heavy speculation.
We're generally somewhere between the extreme anal-retentive end of the spectrum (called "deletionists") and the anything-goes end (called "inclusionists"). Cooking involves a lot of subjectivity, to the point where some people questioned if a Q&A site on it could work at all (with activity as a metric, it certainly has), but on the other hand we don't want the site to turn into a discussion forum, because there are already plenty of good ones (eGullet and Chowhound, to name the two most obvious).
We were also one of the first Stack Exchange sites, which is one of the reasons we have a "brand name" while most sites don't. So our culture formed around an initial intent to attract the same level of expertise and objectivity as Stack Overflow. Other, later sites have lowered the bar, sometimes to no ill effect (Apple/Ask Different) and sometimes with serious problems (like the Atheism site that was shut down after a few weeks).
I don't know how much any of that helps you; I think if you spend much time on other sites, you'll get an intuitive feel for what's universal and what's site-specific. I am or was once active on 4 different sites and yes, there are major differences in culture, but at the end of the day they all basically work the same way.
You might also want to look at Meta Stack Overflow's [FAQ] tag if you want to see some background information dating back even further than the birth of this site. It's the unofficial meta site for the entire SE network.
As for what keeps you coming, well, that's been answered too!