Pacifist +max influence picks
from
Stardock Forums
Works wonders.. in the beginning you can immediately start getting neighbours to convert to you (4 torian & 1 arcanean worlds within first 2 years!) 
As for starbases, which aliens can react negatively too, you dont really even need them for culture conversion.. except much later when there isnt more than you and maybe 2 others.
For my latest game I went saintly for the purpose of staying outside wars, and no bases until after 2210, yet by 2219 the galaxy had turned blue and almost all worlds had gone human without a single shot fired!
AI: Normal (all)
Other picks: pop growth & science+10 iirc
Galaxy: Medium, tight clusters, abudant worlds.
As for starbases, which aliens can react negatively too, you dont really even need them for culture conversion.. except much later when there isnt more than you and maybe 2 others.
For my latest game I went saintly for the purpose of staying outside wars, and no bases until after 2210, yet by 2219 the galaxy had turned blue and almost all worlds had gone human without a single shot fired!
AI: Normal (all)
Other picks: pop growth & science+10 iirc
Galaxy: Medium, tight clusters, abudant worlds.