It's hard to provide suggestions for "most" mod packs, since the actual mod list can vary so much.
Early game I usually use something based on coal or charcoal. If they're available, survivalist generators are very efficient and cheap, but slow.
Mid game, I either build a big tree farm to supply me with charcoal, or pump lava from the Nether. Charcoal would usually get used to generate steam, then the steam used to produce power.
Late game normally means some sort of nuclear power -- typically Big Reactors or Mekanism, though there are some more exotic options too.
For power storage, I usually start with a battery of some sort -- Thermal Expansion's Energy Cells, Mekanism's Energy cube, or the small capacitor from Ender IO. Something like that. Mid game is the same, but maybe with a higher capacity battery. Late game calls for one of the big multi-block power storage systems. Something like that pretty Draconic Evolution energy storage ball, a big block of Ender IO capacitor banks, or a Mekanism Induction Matrix.