In Dishonored, the world shifts in response to your actions - if you've killed a lot of people, you encounter more rats and shambling infected, otherwise, you get less of them. I'm also pretty sure you get other things - when I played the game a second time - non-lethally, I ran accross a guard and his sister near the beginning of the game - the overseers wanted to take her in for practicing black magic which she, and her brother, claimed was a lie. I didn't see them when I played a murderous psychopath the first time...well, then again, I could have missed them, dunno. But there are other small shifts and nuances here and there to reflect how you behave.
In Bloodlines you get changes in the dialogue choices depending on how high your karma meter is. Normally, you get some variation of the good-ish, normal-ish and evil-ish response when talking although the difference isn't Jesus vs Charles Manson. Well, in some dialogues you can gain or lose a point in your karma meter, too, in which case the difference tends to be bigger. However, if you're low on the karma meter, you get more and more asshole-ish responses. In the instances where you can gain/lose/do nothing with points, you might even not get the line that would lead to increase in morality. Heck, you get dialogues where instead of good-ish, evil-ish, neutral-ish, you instead have genuinely malevolent, snarky but overall neutral and neutral instead. Or sometimes it's two responses that lead to karma loss and one that is neutral. It is a downward spiral. While moral characters get to express disgust at some vile acts, evil characters instead celebrate it.
In KOTOR and KOTOR 2, your character's looks change depending on which side of the force they are on, and how far in. A neutral character looks, well, normal, a light side character looks slightly more healthy and alive, while a dark side character looks rather different - shrivelled, scarred and almost like walking corpses. In KOTOR 2 in particular, some NPCs would remark upon it asking if the character is sick or something. Some companions, on the other hand, would mention that they know which path you're heading and they aren't happy.
Then there is Fable, where killing bandits would make you look like Jesus (complete with a halo) and being a douche would turn you into the devil (horns, glowing red eyes, a cloud of flies following you).
In Medieval: Total War after a battle, you usually capture some of the enemy soldiers. Then you have some options - either let them go, or try to sell them back to your enemy (they get armies back but you get money) or just execute them (the enemy doesn't get any armies). Leaders who usually let enemies go become known as compassionate and get more and more respect. Leaders who slaughter enemies like sheep get a fearsome reputation but even your own troops may mistrust them. Also, I believe leaders got other traits to reflect what they've done - those who do a lot of sieges get perks related to that and similar.
I'm not entirely sure if that counts but in Dark Sector you play a guy infected with a...virus, I think, or whatever it is, it's slowly mutating him - it starts off with just the left arm being different but it progresses until his whole body is changed. The changes occur in cutscenes, though.