Tech maniac

Research every (non-infinite) technology - the whole finite tech tree. The infinite research techs that repeat forever (mining productivity, weapon damage and the like) don't need maxing; you just need every tech that has a final level completed. With Space Age installed that includes all the planet tech lines, so it's a genuine endgame science slog - keep the labs fed and it'll tick over. See Research with promethium, since the last techs need the exotic sciences.