Which 'wonder-techs' should we research first?

[Chieftess]

Ok, this is a "companion poll" to the Wonder Building poll. There's 3 techs that are needed, 1 of which requires an earlier tech.

Fission - Allows the UN (triggers diplomatic victory condition) and Manhatten (good for prebuilding)
Computers - Allows SETI
Genetics - Allows Cure for Cancer (CFC) and Longevity.

 

[Bill_in_PDX]

I have a difficult time selecting a choice here. Even in a space ship or culture victory path it is vital to grab fission and the UN first to deny that victory to other civs.