Just randomly curious / wondering here.
The sort of question that doesn't really fit in any one sub-section so I put it here.
Anyway, my answer:
I tend to drift twords ice CASUC reactors. Be it with (Singularity) Compressors or loads of the glacial precipitators from the thermal expansion sub-mob.
Right now i've got two ice CASUC reactors in my world. The one in the overworld I built first with singularity compressors and snow golems in a far flung taiga biome for the snowballs. Number two is the one I built in the Twilight Forest (after I discovered thermal expansion) Discovered one needs 60 of the precipitators as they make one ice every 6 seconds or so.
Expensive setup though, hence the "endgame" factor. need 5 MFSU's total. 4 to absorb power from the reactor and turn it on/off. (redstone signals and BC3 gates both required to toggle the RS Latch) and one to be the point where power is actually used at.