Cyzada, true, but 15% would turn that 14 into a 16 on landing
My current favorite combo is 15% PQ and +1 to sensors. The sensor bonus lets my colony ships do their own scouting. It doesn't sound like much until you try it, but when you're dealing with the itty-bitty sensor rating of a colony ship, the boost seems huge.
On the other hand, I'm only playing large and larger, so I haven't finished enough games to have a decent opinion of all the others. I'm not big on the trade route bonus, as I usually hit the 10-trade route limit before my boosted research abilities cause me to fund at less than 100%.
I've played around with other Parties, but always come back to Federalist. I thought that the Mercantile Party would be my favorite, but I just don't have that many times that a 20% increase in trade is more money than a 20% increase in economy, and as for espionage, I set the minimum amount of espionage as soon as I meet a new race and never have a lack of espionage. After all, there are all these +5% espionage bonuses in the anomolies, and they're additive, not multiplicitave (ack, that looks wrong but I can't remember how to spell it), so there's not as much a difference between a +100% bonus and a +120% bonus.
The Parties that increase research and production are fine, though early on I tend to run at less than 100% funding with them.