I use the search and sky shards, until they put in an actual search function guild store search is bounds ahead of the normal guild store system but still not too great really.
I try not to use many addons, or it begins to take away the experience pretty quickly, but another I have to have is LootDrop, tells me what i'm autolooting so I don't have to sift through everything. Also provides a quick xp ticker for quests and kills.
I'll need to look into some more mods here soon probably, see if anything new has popped up.