You mean like in the destruction tree where you can get perks that turn people into ash piles or send enemies running away like living torches? Or in the melee perks where you can decapitate opponents, or in...
There are some interesting perks IMO:
1/2-handed: They have weapon specific perks and modifications to powerattacks in addition to basic weapon damage.
Heavy Armor: In addition to increase AR there are less stagger, more unarmed damage, less falling damage and removal of movement and weight penalties. Light armor have a increased stamina regen perk and removal of the movement penalty.
Destruction have the 3 modifications to the elemental spells(deep freeze etc.) and Impact which makes dual charging more useful.
Restoration: Recovery gives increased magica regen, Avoid Death gives a daily emergency heal, Necromage make your spells more powerful against undead, respite and regeneration increase the effectiveness of healing spells and ward absorb makes wards more useful.
Archery: stegger possibility, increased speed with drawn bow, slow motion zoom and draw bow faster.
Enchanting: Soul siphon is pretty cool. When you kill a beast with your weapon it get a small recharge.
Illusion: The Master of the Mind allows you to manipulate undead, atomatons and daedra.
These are just some of the perks that are not simple X% more damage or cost reduction. I simply do not see how the perks do not define your character.