I enjoy fighting dragons (Usually) but Bethesda really played them up much too much. The dragons really needed to be:
1. Bigger - Not insanely huge or anything, but enough to be able to walk underneath it dodge attacks and cut away at it from below.
2. Rarer - Can't seem to walk down the street without getting attacked by a goddamn dragon.
3. Stronger - Not saying insanely strong or anything, but aside from their ridiculous "You're Past a Certain Percent of HP So I Can One Hit Kill You Attack" they aren't really a huge threat. They at least needed to be more threatening than common wildlife. (Bears, mammoths, giants, etc. are all more threatening than they are)
4. Telegraph Their Attacks - Really, what annoys me most about fighting them, is that their extremely powerful tail and bite attacks aren't telegraphed at all, they can pull them out of nowhere. Sure, that isn't a problem for Heavy Armored characters with a ton of defense, but what about Light Armor? I don't fancy spending a long time slowly whittling down it's health with arrows, that isn't fun. Not to mention it has a "You're Past a Certain Percent of HP So I Can One Hit Kill You" attack, which comes right out of nowhere. It would be different if a faster character could get behind the dragon but...
5. Needs to Turn Slower - The dragons seem to pivot on an axis when they turn for some reason. It's futile to try to run away from their breath attacks, or get behind them to avoid their aforementioned one hit kill attack because they turn faster than you can flank them.
It's really obvious that the game's combat system just isn't very well suited to fighting big enemies, which is a shame.