Most efficient way to list 'popular' items on very high load website

[eluser]marcoss[/eluser]
I use (and recommend) the "summary" table approach, updated every hour maybe.

Regarding JOIN's vs sub-queries, i have to agree that the former are slower on MySQL (using MyISAM), maybe you won't notice it with just one query, but try usinf multiple JOINS vs multiple sub-queries and you will spot the difference.