Love the coins for the unlocks...
1. Rocket Boost (agree with Eefluxx)
2. Unlocking speeder license sooner for lower level toons. It was great having a level 50 speeder on my level 40 Knight. It made Voss, Belsavis and Hoth so much easier and faster.
3. Repair droid - This is a must for anyone that does Ops, but I even like it on my lower levels as you can buy medpacs from the droid and sell your junk.
4. XP Boost - Playing a new toon trying to get to 50 as fast as possible. This makes is easy.
5. Speed up the cool down on Quick Travel.
I like the packs too, but I get a speeder, dancers top and torso armor in every pack....You can't give away those and you can't sell them to a vendor.