well back in the Alliance, the larger org there is Athen Palladins and they are all very active in US timezone's and always has higher lvl toons there and a mix of lower too, as does ATC there's always something to do, but it may not be the thing you want to do at the time, and maybe that's the problem.
Of the orgs ive seen and been in, that Alliance always has something going on, and 3-4 we have been in together, but Aliance orgs seem to be the busiest. Its easy to make friends there, but also easy to have drama and make enemies, but that's any game i think.
-Meritosthene