Lists of individual wealthiest stars can be found, but I'm interested in the best star constellations overall where I can take one or two extended trips with a full complement of cargo modules (nine or ten), landers and fuel, and loot the most biology (or rainbow worlds) and minerals possible. This would be for around mid-game, where I just want to complete all the building up quickly, buy all the tech upgrades and fighters I need, and then proceed to go through the rest of the game plot from a position of strength.
My current favorite target for this is Vulpeculae, as it seems to have lots of both, a Melnorme visit point, and it has plot points too. But I haven't visited every system in the game, so I thought there might be others I haven't found. Since part of the point is to acquire bio for tech upgrades, a lone supergiant (i.e. Zeeman) or other high-risk-only destination won't do for this purpose, even if it's loaded.