I just finished (I think) my power setup in our current world. Haven't really used anything besides boilers before, but this time I tried the compact windmills (Monster).
They have a fairly big cost in terms of iron (probably at around 100k total now), but it's a nice step up from boilers in terms of output without FPS / TPS impact. They're convenient to place high up in the air out of the way, and then teleport the power down using power converters and tesseracts.
I also like them because they give a reason to go through with the IC2 mass fab setup ordeal (for iridium rotors) and something to use quarried resources on.
Output from the setup is a constant 65k RF/t (16384 EU/t) without any maintenance or fuel.