Harnessing of Spirit (below 46) &
Focus of Spirit/
Focus of Soul (46+) were really nice Shaman buffs that stack with the Aego line of spells, and possibly with the Druid
Protection of the Glades line of spells, which is also a good one for HP.
I know, at least until a certain point, that you could even stack HoS/FoS with regular STR/DEX buffs if the stat buffs were cast first, but I think that was removed on live at some point, especially since +130 str & +87 dex @ level 46 from 3 buffs, then +135 str & +120 dex @ level 60 with 3 buffs was a little unbalanced, especially since you could cast them on most noobs.