The difficulty is fine for most of Skyrim, but there are some unusual discrepancies.
Dragons, specifically the generic ones, are a bit too easy. For the most part, I find the biggest issue is getting them to land. I've fought nine so far: the first storyline one by the tower outside Whiterun, seven generic dragons, and recently my first blood dragon... in Riverwood. It wasn't there when I went into the trader, but all hell broke loose when I went out. Of these, the ones which gave me the most trouble were the ones which took the longest to land; one fight took probably around 15-20 minutes, mostly because I couldn't figure out how to get close enough to the dragon (Autumnwatch Towers, or something like that), which was constantly hopping between the tops of two towers, a ledge (holding a shout-word-shrine-thing), and a couple of the cliffs nearby. It boiled down to running down the steps of one tower, waiting for the dragon to land on it, and running to the top quickly to get a couple quick hits in before it flew off. Eventually, it decided to land in the forest below the towers for some strange reason. Another trouble-maker was coupled with my first encounter with a Dragon Priest, but running away from the priest was all it took (no way I could handle them both); the dragon landed immediately after (lucky me), making for an easy kill. I then went to kill the dragon priest afterward without too much trouble.
However, once they're on the ground? It's all over. Shield bashing (no perks required) staggers just about every dragon I've come across, allowing for plenty of time to wail on it without fear of reprisal. Their melee damage isn't too impressive either. Being a Nord, and most of the dragons I've fought breathing frost instead of fire, has minimized the threat of their ranged damage as well.
Yes, I am playing a melee-centric character (sword & board).
No, I haven't got the "create a storm" nor the "force dragon to land" shouts yet.
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Where I've had the most trouble is enemy spell-casters, as well as large groups of enemies in general (groups of spell-casters being the most troublesome, particularly when a boss-type enemy is among them). Still, the biggest issue for me is closing the gap; if I get in close, it's over very quickly. Unfortunately, a lot of spell damage drains you stamina as well; the inability to sprint towards your target quickly becomes a problem. The whirlwind dash and unrelenting force shouts (both of which are storyline shouts) can be useful, closing the gap or staggering them respectively. Shield bashing is again useful at staggering spell-casters.
The only other problems I've had were the times I got careless while fighting groups. Coupled with my substandard healing spells and forgetfulness to stock health potions (I literally have no issues with most melee enemies, seldom have to heal at all), I can find myself at low health and unable to handle all the foes I'm fighting. Groups of spell-casters make closing the game very hard, and those which throw out powerful spells (fireballs are the worst I've seen so far). I got armour up the wazoo and a good shield, which means I barely take any physical damage; but that isn't too useful when they enemies are out of reach and not dealing physical damage now, is it?
There was also that one time I tried to pull a giant all alone, and ended up pulling him with two mammoths. I managed, but it wasn't pretty.
On the bright side, now that I've finally maxed out smithing... I've decided to select the Atronach stonesign (came across it not too long ago exploring a nearby ruin). The tables shall be turning shortly.