Oftentimes people complain about levitation as a spell being cut, and while it's a cool spell and all, I can understand how it'd be a coding nightmare for the devs and thus much easier for them to cut.
But only now (for some reason) I just realized Skyrim is missing http://www.uesp.net/wiki/Oblivion:Silence: a spell to prevent enemy mages from casting any spells.
Likewise, while present as an enchant, the http://www.uesp.net/wiki/Oblivion:Feather spell is completely absent.
There's also an absense of Reflect spell and Reflect Damage, which, while I could understand fully if they didn't want these to exist to the extent they existed in Oblivion (100% of both possible), they're quite fair in small doses. Hell, even Absorb spell doesn't exist as a spell and is limited solely to enchants and the Atronach sign.
Finally, in what was probably a horrendous balance decision on behalf of a fear of how strong it could potentially be, "Weakness to _____" spells are gone. This spell type was the type that singlehandedly made destruction magic viable in Oblivion.
So why? I don't get why it was at all neccesary to cut any of these. Effects like Feather, Absorb spell and Reflect damage exist in code form, but their uses are highly limited, found only as enchants or spell/perk effects. With spellmaking cut, there's no fear of the player making a broken 100% spell with these, and thus the devs were free to choose the exact effect and magicka cost they desired for these. Instead, they opted to just not include them. And Silence, a highly practical spell for any mage dungeons, is just COMPLETELY gone.
I just don't understand why magic got cut down to size so much, especially given how horrendously awful mages in Skyrim are in end-game compared to the other two. (Warrior just piledrives everything, Thief oneshots from the shadows, Mages spam spells all day and have to kite a bit)