What about a 'fun' or 'open-ended' version (shadow site?) of SO similar to Meta SO?
924
Give each site a parallel site for polling, recommendations and subjective-ish stuff
105600
Allow diamond moderators to create tag synonyms on their meta sites from the synonyms page?
18679
How do per-site Metas differ from Meta Stack Exchange, and where should I go to ask my question?
57164
Meta Meta Stack Overflow?
143472
Which Stack Exchange site is fit for asking domains and hosting related questions?
150649
How do I do awesome refreshless page changes like GitHub do?
33644
Should we have a subjective version of every Stack Exchange site?
19435
Can I use the Stack Exchange concept in my own sites?
59819
More badges for being a site enthusiast
6801
Is Stack Exchange / Stack Overflow available for private or internal use?
92539
Inline Editing for Stack Exchange Sites
119857
Could we allow child Meta questions to be closed as duplicates of Meta.SE ones?
23667
Build and strengthen the Stack Exchange community with "crossover questions" between sites
70664
Allow me to get notifications for new Meta posts, like mods do
20138
Allow cross-posting of questions to more than one SO site
34292
What should we do about Stack Overflow-specific questions on Meta SE?
89171
Is there a browser that allows different instances that don't use the same cookie for the same site?