Though most upgrades have their places of usefulness, some upgrades are simply tiny cards of concentrated awesomeness. Each of us probably has a list of them by now, so here's a spot to post your love for them.
Mine is a list of 6 at the moment, and I do not have a particular order for these.
- Advanced Sensors: The reason that Initiative is a big deal is primarily in Action Advantage in very specific places. Advanced Sensors means that your ship ALWAYS have Action Advantage, regardless of flightpath. It also means you never have to lose your action to a Red Maneuver, and can be comboed with Engine Upgrades to give you more positioning choices than Navigator, and you've got one heck of a thing.
- R2-D2: Guarantee for regenerating the better sort of health, you say? If it is able to do it once, it is even with a Shield Upgrade, with whom it shares a cost. If it is able to do it twice, it is slightly less than Chewbacca, with whom it shares a cost. Three times or more? You've got the survivability of a Large-Base Ship all of a sudden. Considering you can use Draw Their Fire to absorb crits dealt to friendly ships into your technically-infinite health pool, and I wish that a third ship with an Astromech Slot would be invented already!
- Push the Limit: The reason that Advanced Ties ever see competitive play is that Darth Vader comes with this already attached. General consensus puts this as the best upgrade in the game, and I cannot truly disagree. It'd still see play for 5 points, in my opinion.
- Expert Handling: The beauty of this upgrade isn't its ability to strip target-locks off of your ship. That's just gravy. The fact that you can give a Barrel-Roll to any ship with an EPT slot for 2 points is good for small-based ships, but on a Falcon or Firespray, that barrel roll becomes ridiculous. Seriously, from the right angle it can get you from Range 1 to out of range, or vice versa!
- Gunner: If I shoot at someone, they're bloody well going to get hit. "Han Shoots First" fleets have proven the worth of this Wookie.
- Proton Bombs : Faceup damage are intended to be powerful, to the point of crippling the ships they're dealt to. 7 of the 33 card deck are the double-damage Direct Hits, which translate to approximately 1/5 odds of dealing 2 damage for the price of 1 card. Two of those will kill most ships in the game (excluding only the Y-Wing and the Larges), and it only takes 1 to KO an A-Wing . This card brings the other 26 into terrifying vitality in the early game. Moreover, it is free damage. That is, if you've correctly predicted where your opponent will move, it is guaranteed damage that cost you neither action nor attack. It is also one of only 3 bits or ordnance in the game that can damage a person's entire fleet, once again spreading those potentially disastrous crits around like glitter by the air conditioning vents.
So what's your list?