I like the Hardlight shield. It provides good defensive options as if your shields go down you can pop it to buy yourself some time or get back into cover (especially if you were being shot at at long range). It can protect you from nearly any firepower if you notice something incoming (saved myself from scorpion shells). Provides good offensive options sometimes (equip shotgun and pop shield when noticed and start advancing on opponent).
I feel it has good versatility so it's my favorite. Granted it has its weakenesses (slow movement speed and vulnerable from other directions) but I feel those are fair concessions to make for it.