Powered Power Armor in the nexus can make all Power Armors make sense (Even the ones from mods as long as they are tagged as Power Armor in the GECK). The Fallout NV version is perfect but the FO3 version is as buggy as Unity. (The FO3 version was abandoned for the NV version). Basically it puts the "Power" in power armor.
As RangerJosh said, Mk117 Power Armor is also good and is both available here and in the nexus.
There is also the Japanese Power Armor mods which are amazing and kinda bulky too.
There is also the Coyote Reflex Armor, I tried it and I liked it but I can't remember what was so special with it anymore. It still looks cool though.
There is also the Midwestern Power Armors or the Tactics Power Armor.
Last but not the least, there are a lot of Enclave Power Armors like the Colossus XV and the Enclave Relic.
Hope I helped.
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