For a good look at a lightweight list you can take a look at my compilation
WulfPack.
Mostly lightweight addons yet providing all the functionality i consider a must have. A few heavy addons in there that i usualy run only in specific situations are: LightHeaded, QuestHelper, and Recount. IceHud and Autobar are medium weight but i rely on them to much to do without. Have been debating on adding Incubator back in but i just dont find much need for respawn timers anymore, and Combuctor may soon be added replacing movable bags. Not real happy with ItemRack anymore either but dont like most of the other equip addons ive found....