If we're assuming that mesh inserts don't count. 1. Enhanced Vision * 2. Enhanced Hearing * 3. medichines (negating a wound modifier is awesome) 4. Grip Pads** (Both as an implant and as a mod to clothing. massively useful in Low g, Micro g) 5. Neurachem (the obvious force multiplier) * The obvious +20 bonus to Aural/Visual perception is Bomb, But often GM's don't highlight the problems caused by passive sensory interference that would be really common in space. Being able to negate all of those issues with two pieces of gear is a major Boon. The +10 to F2F Kinesics tests is also very handy. ** The +30 climbing bonus makes spending points on the skill almost superfluous. Many players have never considered the effects of Low gravity on friction coefficients, such that accelerating and changing the vector of your momentum makes tactical movement very difficult. As a GM I play this to the hilt requiring frequent free running tests, (pretty much every turn a character is moving above walking speed.) Because it's realistic, I grant characters with grip pads a +10 bonus to freerunning in low G environments if there's any reasonable chance that they can benefit from the additional grip. The same +10 bonus should apply to grappling and defense against being disarmed. My runners up are; Smart Vac Clothing/Suit, Chameleon cloak, Nanodetectors, Eel ware, T-ray emitter. For flavor, all of my characters always own or subscribe to AR Illusions and XP. Because life in habitats mostly sucks without those things.