Sorry, but the answer is going to be..."the one that fits you the best"
All that aside, I'll give you my opinion...
Frame Rank - Dual, Equinox, S25
Component Rank - S25, Dual, Equinox
Wheel Rank - Dual, Equinox, S25
Bang for your buck - Dual, S25, Equinox
The fact of the matter is that all of them are good bikes. If it were me (and I just bought a tri bike within the last few weeks)...I would consider upping my price range a bit and go for the Cervelo P2 SL. The frame is awesome, the components are great, etc. I'm one of those guys that typically wants something new and better the minute I buy something...this is not the case with the P2 SL. I can't imagine wanting another tri bike. It may not be the top of the line like the P3 but it is more bike than I will ever need.
Good luck.
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Fredo, you're my older brother and I love you...but don't ever take sides, with anyone, against the family again...ever.