Sprint - allows one to reach critical weapons quicker/first, jump longer distances, and escape battles. imo, the best one (I use this 99% of the time in matchmaking and have had great success)
Armor Lock - good if you like to rely on your teammates to bail you out or avoid 1-hit-KOs, but not really useful otherwise
Invisibility - good for camping/hiding/sniping, but experienced players closeby will still be able to find you/your general position
Hologram - besides the hologram trick, it is completely useless against decent players (unless you just want them to waste ammo)
Jet Pack - allows one to change elevation/jup obstacles quickly to avoid/do damage and to reach critical weapons first/faster. Unfortunately, many maps are not suited of flying, unless you want to make yourself an easy target for precision weapons.
Evade - good for quick escapes in tight areas, but in the open, the opponent can easily kill you
Drop Shield - great protection against med/long range attacks,
but not really useful otherwise