I use them, either to get effects (like Wall of Flames) ahead of level, or as backups whenever I run my magicka down spamming Destruction. (I may be the only one who doesn't Enchant Magicka away.) As mentioned earlier, my favorite is probably Rahgot's, because of my Bash&Burn tactics. Even if I never recharge it, a momentary pulse uses so little charge that it generally lasts from whenever I'm badass enough to pull it from the ash pile to level 65, when I can buy the spellbook. Another favorite is Jyrik Gauldursons' for shooting down Dragons (While my Magicka recovers.) The Staff of Magnus is a bit more specialized, but can be used for unique applications like torturing Paarthurnax to death with Lesser Ward.
And finally, I also use Staffs of Summoning with Spell Absorption to recover Magicka. If you have 100% Spell Absorbtion (Either as a breton with the Atronach Stone, or with the Dragonborn DLC, Miraak's Robes, Boots/Gloves, the Atronach Perk, and Stone) then you can't summon, because every time you absorb the magicka before the effect takes effect. if the Spell happens to be from a Staff, you can basically use it to drain charge for Magicka. You want at least a Storm Atronach for the most Magicka per Charge, though.