Good old Delver, Monoblue aggro-tempo.
Drop early threats and back them up with counterspells, bounce and card drawing. I feel really rude when I flip delver early and then stop my opponent doing anything relevant. It's actually rather fun being the annoying blue mage.
Ninja of the Deep Hours can draw you loads of cards while resetting Spellstutter Sprite for extra value.
Cloud of Faeries is fantastic, it's a free spell that boosts Spellstutter Sprite's countering ability. It's also evasive to enable Ninja and can cycle away if you draw it late game and you don't want it for some reason.
Spire Golem is a cheap creature that also blocks well.
Bonesplitter can upgrade any creature into a potent threat.
I do like Gush, although I also want to try and fit in Piracy Charm somewhere. Not sure what to cut from the deck though.
Coast watcher is there since protection from green seems handy. There are lots of annoying decks that run green things, such as Elves, madness decks, infect and a dredge deck. Also the hexproof deck, assuming you can Counterspell the trample granting auras.
Curse of Chains locks down decks that win with big annoying creatures.
Hydroblast seems obvious.
Annul is for affinity and hexproof decks.
Dispel is against burn decks and decks that are heavy on counterspells and/or instant speed removal.